Doing something for the last time without realizing that it's your last time doing it. 

(If you think about this one too much, you'll become so paranoid that everything you do, you'll wonder, "Is this the last time?")

EDIT: How appropriate that this was my last blog post for over a year...

I just found this amazing list of writing exercises: 66 Experiments by Charles Bernstein. They're designed for poetry, but who's keeping score? The best, most striking fiction skirts the line between prose and poetry. I love reading an electric bit of prose and feeling slightly shaken. Can a fiction author even do that?? Isn't there a rulebook somewhere that says we aren't allowed to do these things with words?

Remember, these exercises are meant to loosen you up. To break the rules and show you some new tricks to do with your old words. Let yourself get crazy and see where you end up. 

Thanks to my friend Gnome for this one:

That brief period of time when you've finished all the laundry and the only dirty clothes are the ones you're wearing.