I was going to post on this same topic. Every once in a while, I get an isolated bee who wants to mess with me. She starts bumping my face, I turn to run :roll:, she continues bumping the back of my head and trying to lodge in my hair, then I manage to shake her by going into the barn or the garage. I'm amazed at the tenacity of these bees, because when I exit (even 15-20 minutes later) the same angry guard is right back on me :-D. Eventually, she seems to give up, but this may go on for hours.
P.S. - I've also had friendly ones that just want to hang out with me, usually in early Spring, but then I realize that they were just looking for a place to poop...haha