I have on a couple of occasions left the front maxle at home, but fortunately only 20 mins each way to rectify
I have also driven 30 minutes to the start of a ride, then managed to lock myself out of the car with literally everything left inside it.
But I think the best one was when, years ago I was white water kayaking in Scotland with a mate. We’d done 2 or 3 days and rocked up at Bridge of Orchy one morning, boats of the roof, got changed, everything ready then couldn’t find the paddles. we each thought the other was playing a prank.
We’d actually left them by the side of the A82 just north of Fort Bill the previous evening, after doing the lower Spean and Lochy. They weren’t still there of course. We went home. Amazingly, we found out later that some honest soul handed them into the police station in FW.