… You get a song stuck in your head, but it's a really terrible song?
… You have a mind-blowing idea but you can't execute it?
… You post things on a website and people don't read them?
… You know a really good piece of music, but you'd never be able to recite the title?
… You start drawing or painting something, and you start adding stuff to it to make it look better and it starts looking messed up, so you keep doing that until it looks like complete crap even though you had something awesome going?
Post moments in life you absolutely hate.