We can hardly blame her for this one. It's a very easy mistake to make!
Emma Watson popped in for a chat with Jimmy Fallon. Before they got down to it, they addressed the elephant in the room.
The last time Emma was on the show, it was her first encounter with him. He complimented her outfit, and before she let him say anything further, she attempted to pay him a compliment back.
However, it went completely pear shaped.
Emma confidently complimented him on the 'Halloween candy thing' that he does. Only to be told that it was Jimmy Kimmel.
Well, that's awkward.
Emma discussed a whole lot more, including how she had to attend 'Princess Camp' during filming for Beauty and the Beast.
Watch her interview below: