Mannone feels going through his Athens humiliation - where he made a complete hash of attempting to scissors-kick the ball clear as it bounced on into the empty net - saw him come out a stronger person.
"It is a game where, I know you find it crazy, but it was a good lesson for me," he said.
"I had another mind at the time. It was almost one year ago and my mentality was I was nearly away from Arsenal. I was expected to go on loan. I didn't feel confident.
"I had not played for a year and a half, and at the time, my mind was not ready.
"I did not help myself because I needed to be sharp and always on my toes."