MHF, ha ha, I have a similar one.
I used to work at a dude type ranch when I was 16-17 for free riding. There were approx 40 horses there. I was told to take a bridle and go find Poco for a regular customer to ride. Ok, no prob, Poco was a bay, and one of the biggest horses. They were in a 50 acre field, but they all usually were together so no big deal. I find him, bridle him, and leap up on to his 17 hand high back. (I was 16, remember? No way could I do that now without a stool. Sigh.)
So we canter in bareback, and stop in front of the head wrangler. Everyone who worked there was just standing staring, mouths agape. Then head wranglers hisses "Hurry up, take him back to the field! Don't let the boss see you!"
Turns out I had grabbed Nordic, not Poco. Nordic was the owners' horse, and no one, I mean NO ONE else was allowed to ride him. Ever. In fact, no one else had ever been on his back before but the owner. Luckily, no one told, and I managed to go exchange the forbidden big bay with the proper one.
The real facepalm was that Nordic's face was all brown, while Poco had a big white stripe!! Ha! Newbie!!