I have several:
“Hiking” to a spot in Seattle to realize I left my batteries in the car. Had it go back and get them which ruined the mood.
Getting booted from a perimeter road from DIA by the police to go and drive to a rental car parking lot and getting booted by the owners :(
Arriving to the In-N-Out on Sepulveda with a camera battery of 40%. And a Sony battery, mind you.
Arriving to spot and forgetting my long lens, meaning I had a 16-35 and a 55mm only.
And probably the most embarrassing, with my dad in the ops car at DIA, and having to make a UA 77W wait to cross in front. Not my fault, but the disapproving looks from the cockpit and the very sarcastic “wave” when I waved back was embarrassing. This was the result: