I've gone out to a group ride, gotten the bike out of the car in a pre-caffeine muddle, and put the back wheel on backwards (that's right, chain not lined up with derailleur). Funny thing, moving the pedals didn't move the bike! The group was just pulling off... but they stopped and waited while I fixed it...

... and I'm still working on that fear of not being strong enough to get the bike going, and scootering across a whole intersection... but it's getting bette.r