Aesop Amnesia/Playing With

Basic Trope: A character learns a valuable life lesson...and promptly forgets it.

Straight: Bob learns that it's wrong to bully others. A couple of episodes later, he's back to bullying.
Exaggerated: Alice learns that it's wrong to litter. In the very next scene, she's pouring paint down a storm drain.
Downplayed: Bob learns a lesson about bullying. He sticks with it a few episodes before eventually relapsing.
Justified:
- Engrained bad habits are hard to break; it takes sustained effort to remember to do better.
- Aesop Ju Jitsu
Inverted: Alice and Bob remember each Aesop forever, and even when they break them, show knowledge that they shouldn't, or explain their need to do so.
Subverted: Bob remembers not to bully others (in a series where this is not normally the case.)
Double Subverted: But it's a setup for a We Want Our Jerk Back episode, with even his former victims asking him to return to bully behavior.
Zig Zagged: Alice and Bob remember some Aesops, forget some Aesops and outright reject a few.
Parodied: Alice and Bob's inability to retain information extends to all other forms of learning. Which is why after eight seasons they're still in fourth grade. Miss Aesop, their teacher, has taken to drink.
Deconstructed: Bob never learns his lesson about bullying because just repeating that it's wrong doesn't change his personality flaws. He eventually goes to prison for assault and battery.
Reconstructed: Bob rehabilitates in prison.
Averted: Characters in the series learn life lessons normally, without having to have them spelled out. Character development happens in a realistic fashion and at a plausible pace.
Enforced: "Bullying is Bob's one defining character trait. We can't have him lose it; besides, Viewers Are Goldfish, they won't notice that we've used this life lesson before."
Lampshaded: "No matter how many times Alice learns that littering is wrong, she still does it. You think there's maybe something wrong with her?"
Invoked: "Dammit, us litter pickers need to get Alice back into littering before we're out of a job! Get some chloroform."
Defied: Alice keeps a checklist of things she's learned, and consults it frequently to help correct her bad habits.
Discussed: "Aw, all right, you have a point; bullying is bad." "You better not forget that tomorrow!" "Hey, what do you think I am, a TV character?"
Conversed: "I'm smarter than Alice on Generic Sitcom, 'cause I remember not to litter!"

And so we've learned...learned...I'm sure it was a very valuable lesson about life. Now, back to Aesop Amnesia!