Let's just say you're an actor and the scene you're doing calls for you to cry. Quick! You have to think of something sad!
Here's a very sad thought - in fact, it's happened to me (only just this morning): You go to the kitchen to rinse out your coffee cup and just a split-second too late you realize there was just the tiniest bit left. You watch, as if in slow motion, the coffee swirl around and drain before disappearing forever. In that moment, you consider licking the sink but think better of it, realizing that even though you love it more than words can say it's better to just let it go.
Your heart swells as you consider what can never be recovered but cherish the fleeting bliss you once had.
Oh, god . . . I can't go on . . . .