Be Vigilant*

Sure. It's the middle of the day and you've got no particular plans. Why not take a walk in the park? It's right there, and you mean to use it more often, after all (TRUE STORY!).

It seems harmless enough, but it's also a good way to loose your keys (TRUE STORY!). Then you've got a problem to deal with, which is pretty much a downgrade from "no particular plans."

"Doing Stuff: A Real Roll of the Dice"
-Tagline for a new pamphlet on doing stuff

*Alternate tagline for a new pamphlet on doing stuff