Fleeting Passionate Hobbies

A character trait mostly in sitcoms, but occasionally played straight. A character gets passionately involved in hobbies for short amounts of time, before putting them aside and starting something else. May set up a series that is essentially Hobby of the Week or something similar.

Compare Compressed Vice when this is done with character flaws, and Why Do You Keep Changing Jobs? when it's done with careers.

If the character supposedly always was an enthusiast in today's hobby rather than picking up something new, see Backstory of the Day.

Anime and Manga
"Izaya: That's why I make it my hobby to stomp on girls' cell phones. HA HA HA HA HA!...Bored now. Stomping on girls' cell phones is no longer my hobby!"
 * The Melancholy of Haruhi Suzumiya: Haruhi tried out every club on campus, excelled in every one, and quickly got bored with them.
 * Durarara!!'s Izaya Orihara is evidentially very flighty when it comes to hobbies.


 * Maon of Tamayura grew up changing dreams all the time.

Comics

 * In the comic strip FoxTrot: the mother, Andy, does this a lot, sometimes becoming briefly addicted to the video games which she criticizes Jason for playing.
 * In the Disney comics, Donald Duck has his scatterbrained cousin Fethry, who was frequently dragging Donald along on his latest interest.

Film

 * Played straight in Adaptation, where the plant expert was formerly an aquarium expert. "Done with fish," as he stated. He was a real person in the non-fiction book on which the movie was based. Sort of.
 * In the dark marital comedy The Ref, Lloyd rips into his wife for this (among many, many other things).
 * In Hot Shots, the hero's love interest Ramada is doing something different every time he sees her, from trick horseback riding to lounge singing to welding. She's officially a psychiatrist.

Literature
"Those who know Bertram Wooster best are aware that he is a man of sudden, strong enthusiasms and that, when in the grip of one of these, he becomes a remorseless machine - tense, absorbed, single-minded."
 * The Wind in the Willows: Mr. Toad is practically the poster boy for this trope. That makes this one Older Than Radio.
 * Losing Joe's Place: Rootbeer Racinette A secondary character and later indispensable plot coupon from Gordon Kormans book. He has a running gag where he gets a new Hobby everyday and later is turned into a variety act by his desperate for money "Friends".
 * Tortall Universe: Keladry states that one of her brothers is like this in Protector of the Small, jumping from great-seeming idea to great-seeming idea. There are some who think that Kel forming crushes on three different boys (Nealan, Cleon, and Domitan, though ) fits too, but as this was over a period of eight years of her teenagerhood it's somewhat debateable.
 * Chet Morton of the Hardy Boys. To be more explicative, he has one virtually one every book, which usually ends up being very important to whatever case the Hardy Boys were investigating.
 * Frank and Joe are hardly any better, in many books the plot is kicked off by one of them suddenly displaying a new hobby or skill they claim to have been into for years but is only now brought up.
 * PG Wodehouse:
 * In Psmith in the City, Psmith's father turns out to have this trait, possibly as a result of his Attention Deficit Ooh Shiny
 * In the Jeeves and Wooster novel Thank You, Jeeves, Bertie Wooster claims to be prone to these, the current one being banjolele-playing. The events of the book see him split with Jeeves and move to the country solely to pursue this hobby,.

Live Action Television

 * Hal from Malcolm in the Middle took up board games, skating, NASCAR, robot building, painting and various others. Lampshaded in one episode that features this happening with DDR: We learn that he and Lois have an agreement that Hal can indulge in these things as long as it doesn't interfere with his job, as they both know the obsession isn't going to last. It's implied that these hobbies are one of the primary causes of their financial difficulties.
 * The Star Trek franchise has various examples:
 * Star Trek the Original Series: Sulu had an interest in botany in one episode (ISTR) and in fencing in another. Also, antique firearms. The novel Death Count runs with this, claiming he picks up a new hobby on every shore leave. It's Word of God—the original 1960's Star Trek Writer's Guide describes Sulu as a serial hobbyist, but this personality trait was only really played up in the early episodes of the series. It's even Lampshaded in "The Naked Time," when Riley mentions that Sulu's passion for botany has switched to fencing. The botany hobby gets briefly mentioned again in the third season episode "The Way To Eden." The fencing also comes up in the rebooted movie.
 * Sure, Benjamin Sisko of Star Trek Deep Space Nine had an interest in Bajoran history from day one, but putting aside a month to assemble an ancient Bajoran solar sailing ship by hand and actually trying to fly it in space? And then never mention it again?
 * One episode of Star Trek Voyager has Paris getting obsessed with repairing a starship named Alice. It turns out that the ship (who was sentient) telepathically created the obsession so that she can be repaired and taken home. Also his constantly changing interest in various holodeck simulations. And his interest in "classical" American history. And his sudden desire to become a holo-novelist. And his...
 * Chakotay was also particularly prone to this as well; eventually this was turned into a Running Gag by reviewer SF Debris: "because this week Chakotay has always been into ANTHROPOLOGY!".
 * Justified in the case of The Doctor, as he was deliberately trying out different hobbies in his quest for individuality.
 * The Brady Bunch: Greg had sudden hobbies of surfing and photography. Justified in the case of surfing, as Barry Williams was an avid surfer in Real Life; it had just never come up during a plot before.
 * Chet, from The Hardy Boys series is prone to this. Shot Put, Ventriloquism, Scrimshaw, Spelunking...
 * In each episode of The Pretender, Jarod would engage in fleeting obsessions with an episode-relevant skill and/or some childhood item previously denied him at The Centre, taking the time to learn everything he possibly can about it. This goes along with his talent of being able to become anyone he wants to, meaning he's a very very quick study.
 * Tommy Oliver from the Power Rangers metaseries suffers from this seasonally. He's had brief but intense interest in martial arts (he stays good, but he only did it purely for pleasure in the first season or two), American football, and racecar driving. Most notably, he actually got a job doing that last one immediately following high school graduation, only to show up seven years later as a high school science teacher (with a Ph.D. in Paleontology) who'd retired from being a successful mad scientist who worked with biological experiments. It is unknown how, or if, he ever finds the time to sleep.
 * Ellen of The Adventures of Pete and Pete would show up with different passions and/or different jobs. She was absolutely fixated on each one for the episode it lasted for—marching band, woodshop, and vending machine repair in one episode.
 * Edina in Absolutely Fabulous does this, in cycles of three weeks according to daughter Saffie. Phases include Japanese decor, living through a personal organizer, colonic irrigation, modern art and adopting a Rumanian baby (the last, thankfully, a dream).
 * The eponymous Joan from Joan of Arcadia eventually developed this, as God's instructions lead her to adopt new hobbies every week, which would often be abandoned by the time the mission was over.
 * In the Big Bang Theory episode where Sheldon loses his job. He claimed that his unemployment finally gave him the time he needed to pursue his interests, but he couldn't stick to one hobby!
 * In the Thirty Rock pilot, Jack Donaghy uses his market research knowledge to correctly guess that every two years Liz Lemon takes up knitting for a week.
 * In Home Improvement, Tim's neighbor Wilson is always involved in some strange new activity just before he gives Tim some advice.

Tabletop Games

 * In many Dungeons and Dragons settings, the Gnomes are portrayed as tinkerers, and as such will often fall under this trope. In less grim settings (or occasionally, grim settings), the Elves might as well, especially if they are carefree or hedonistic.
 * The Orren, otterfolk of the World Tree setting, have this as one of their hats. They are stereotypically described as having many interests that they flit between and learning new skills easily, the latter of which is represented in the rules with a chance to gain extra skill levels.

Web Comics

 * Sally of Darths and Droids is a "young enough to make sense" example, as she keeps changing what she wants to be when she grows up.
 * Aki of Aki Alliance drops in and out of so many school clubs that the entirety of her class hates her for not sticking with them.

Western Animation

 * Family Guy: Peter Griffin, lampshaded in recent seasons where his family finds out they can distract him just by bringing up some obscure hobby. See also: the Petercopter and the Hindenpeter (exactly what they say on the tin)
 * Taken to an extreme in The Simpsons: Homer has a new 'life-long dream' every time he brings it up, usually followed by Marge reminding him what his last lifelong dream was. Also he consoles Bart by saying that if he doesn't want to learn the guitar, he can just put in the closet with his karate uniform and unicycle. Bart is 10, though.