2 weeks into my current job.
Me, to some random guy: “hey, any idea where Bill is?”
“I’m Bill”
“You don’t look like Bill”
“Maybe you mean someone else?”
“You know, Bill, the guy who sits at this desk over here” picks up picture of Bill and his family from his desk “oh hi Bill. So I had a question about this project”
Also, we’ve got two guys named Matt and Mark, and I had trouble remembering which was which for a while. One of them is my boss’s boss, the other is that guys boss. So I’d just call them “the bald one” or “the furry one”. They didn’t seem to mind much