Figuring out where to attach a carbon monoxide alarm to my wall:

Initial, naive thought: I should make it very visible so when it goes off I can quickly see whether there's a real problem or just a puff of dust or whatever.

Carefully considered thought, with knowledge of self: I don't have a level. So I'm going to install this thing somewhat off-level. I should install it someplace where I won't see it most of the time, because that's going to bug me.

Later:

Good call on installing that alarm around the corner from where I can see it all the time; makes it much easier to ignore that hole I drilled in the wrong spot.