(noun) An error; a blunder.
"Look at every mistake as an opportunity to learn and improve."
"Mistakes are acceptable if you learn from them; unacceptable if you don't."
"I'm selfish, impatient and a little insecure. I make mistakes, I am out of control and at times hard to handle. But if you can't handle me at my worst, then you sure as hell don't deserve me at my best."