Oh lighten' up a little! Life is to short to worry about it! (and by the way, unless you ride in a protective bubble, you share the road, and sport, with any and everything you can possibly imagine!
Scary ain't it??)
I use to put my gas cap on the driver's seat. Now I put it on the gas pump out of the way with the screw up, out of the dirt. With the gas door I don't forget the cap.