Bonus points if the boom mic drops into frame

literally me

It happened on Doctor Who one time. I laughed my ass off because they're known for being really good about editing/line of sight so you don't see them.
(Unicorn and the Wasp, if you're interested. The reflection is on the dresser when the Doctor and Donna investigate the murder of the professor)

I thought I was alone in doing that

I tend to watch shows/movies that don't suck, so I spend my time paying attention to what's going on.