you reach into your pocket in the checkout lane at the grocery store and find a handful of dog treats.
I've also heard about this happening to moms. One time my mom ran her hand through her hair at the grocery store only to find she was still sporting the hair-do my little sister had given her, complete with the sparkly butterfly clips I wore in the 6th grade. Sometimes moms realize they have baby spit-up all over their shoulder.
One time in high school I was wearing a hooded sweatshirt and during class, I reached into the hood and pulled out a sock that had gotten stuck in there in the laundry. What if it had been my dad's underwear or something? I would have been mortified. My dad is probably mortified that I mentioned his underdrawers on the internet.