Time Marches On

"You're older than you've ever been, and now you're even older,

and now you're even older, and now you're even older.

You're older than you've ever been, and now you're even older,

and now you're older still.

Time is marching on, and time... is still marching on."

- --They Might Be Giants, "Older"

Any story must be written over some period of time. It can only be read at a later period (occasionally overlapping, but still later). Usually, this is fine. Some stories remain classics thousands of years after they were written. Others, not so much. The world shifts around them and they become less plausible, less interesting, less relevant, less funny, or even less comprehensible.

Tropes that usually fall into this category:
 * Cosmetically Advanced Prequel
 * Have a Gay Old Time
 * Get Thee to A Nunnery
 * Funny Aneurysm Moment
 * The Great Politics Mess-Up
 * History Marches On
 * Long Runner Tech Marches On
 * Not So Crazy Anymore
 * Once-Acceptable Targets
 * Science Marches On
 * Society Marches On
 * Steam Never Dies
 * Technology Marches On
 * Zeerust
 * Zeerust Canon
 * Values Dissonance
 * Deliberate Values Dissonance
 * Fair for Its Day