Hate to admit it, but happened to me twice. Recently... Must be Alzheimers kicking in....
I took all my stuff to work so I could go straight to the gig. Put my bass in a closet at work, didn't want to leave it in the hot car all day. Running late at work, leave in a hurry, of course, leave the bass in the closet. Luckily I remembered in time.... to go home to get a backup and still make the gig.
Then just last month... Loaded the car, left the bass for last. Something distracted me, off I go. Got off the freeway thinking, I don't remember loading the bass... had to go all the way home, ended up being late to loadin, but had enough time to make the start time, had to really rush setting up.
Good reason to always leave early... and doublecheck your load...
Randy