Same here. My logic is that my toothbrush is in the same room as a device for aerosolizing fecal bacteria, which is kinda gross but also not that different from a lot of other surfaces and environments, and that it's going to collect some amount of stuff floating around. A quick rinse is going to dislodge a good fraction of what has accumulated over the course of a day.

I thought I was just being logical, but apparently I also have a deficit of attention. Okay, then. I guess I'd rather bear that burden than brush my teeth with shi... sorry, I probably should terminate that sentence before I get carried away.