I left my car lights on one day, the first day at a new job and the battery was shot when I went out in the afternoon to drive home. Now that's wholly embarrassing because you need help from people you don't know yet :-)

It proved to be a good opportunity to help my self-esteem though; I was terrified from then on I'd leave my lights on but thinking about myself and my memory (excessively good :-) I decided to trust myself to remember to remind myself to turn off the lights after rain and I did! What's the worst that can happen? Not like your keys have your address on them or make of car, etc.? I have a latch on mine and instantly attach them to the strap of my purse when I take them out of the steering wheel. It's just like any other problem, you don't get that upset when you forget why you came into a room :-) so why get upset over forgetting anything else. I bet you were super busy is why you forgot! Relax some instead.