Tuesday Thread: How Do You Know When To Quit?

As promised, we have two mildly to strongly existential thread prompts this week. The first comes from Culture Study Reader Kate, who asks:

How do you know when to quit vs. when to stick it out? (Something I've been thinking about a lot recently!)

You can apply this one to many different facets of life — books, tv shows, hobbies, long runs, getting a cer…