I'm paranoid about keys after DH locked his keys in the car & my keys were in the house. Guess where house keys were, yes in the car (same key ring). Phone call to try & find his S, no luck. Sat on front wall, luckily a lovely warm summer evening, a neighbour went to get a bunch of keys, still no luck.
Eventually DH had a bright idea, if he climbed over garden wall he could hook the garage keys off the coffee table by the french windows, hand through cat flat & a garden cane. Keys for garage retrieved DH went for his fishing net as he could reach bottom bolts but not top ones. Guess what it worked
I never again went out without my handbag & door keys.
When I go away I always take my spare car keys, if I lock my car & open the boot separately, the boot locks automatically when you close it. I'm paranoid now. Two of my neighbours have spare keys for my house as they feed the cat when I'm away.