You were a mistake + Unimportant =
Haha...You...Get it? YOU're the mistake
"You're the mistake!"
A mis-take. You missed the take.
Lol its actually something that you can do when you do your work
Speaking of your work, do it.
Person 1: i made a mistake on my math test and got a 95%!
Person 2: you get a good score on your test?