Haw.
http://www.daybydaycartoon.com/2008/06/17/#a004683
That's today's Day By Day cartoon, relevancy check to follow.
I've always been somewhat of an "absent-minded professor" type, though not nearly so much now since my sleep problems are being treated (apnea, for a long long time).
Today's cartoon reminded me of the 5-6 times I'd get up in the morning, oh so groggy, hop in the car and start it, settle in to start driving, pat my pants pocket and go "Aw, dammit... what did I do with my keys?"