I've mistaken mannequins for people and people for mannequins so many times than I can count.

Like I would stare at the thing thinking whoa this looks so real and then SURPRISE!
IT MOVES!
IT IS A HUMAN!
WHAT WAS NISHA THINKING?!

then other times,

*knocks on person*

Me: omg I'm so sorry

Person: *no response*

Me: *looks back*

Me: *facepalms*

Me: *bangs head on the wall*

Me: *t-

You get the point...