Or "Don't be bitter." (A line from a particular Life In Hell I kept in my high school locker.)
Or "Uh, uh, uh, 'Splunge!'" (A Graham Chapman line for a Monty Python sketch, and one of many words Chapman made up. I really like that word. It's partly why my Twitter name is Splunge2000.)
Or "Oh what is about to happen?!" (From a s00j live CD.)
Or the prefix "The judges also would've accepted..." (A phrase I picked up from Rick Emerson which I find myself using A LOT.)
I'm easily entertained. I should say easily self-entertained. It's a skill. (Also a budget control. Can make me a cheap date.) All the thinking I think means that I think stuff that would be greatly out-of-context and hard to explain to anyone else. As long as I can explain it to myself, though, it's no problem. (Oh, crap, ANOTHER reason Alzheimer's sucks: possibly forgetting what you find funny. Oh, no.) And being amused is important. It's serious. (Comedians are often deeply serious.)
If something stops being funny as a private joke, it can die a quiet death, to be replaced by other amusing-to-oneself thoughts. It's not like the joke bombed on stage at Carnegie Hall, though if one did, you'd better have a good back-up joke. (My sister-in-law Cindy did stand-up comedy for a class. She learned how important it is to get one last good laugh and stop -- "You've been a great audience, good night!" -- even if you have other jokes you could tell.) Even an audience of yourself is an audience, though. So keep thinking. And keep amusing yourself.
Now what did I say about ending well? That can use work.