The 28-year old came in for Rio Ferdinand in a friendly with Spain earlier this year and he admits his error that gifted David Villa a goal was the point where he had to turn things around in order to again be considered for the national team.
England lost 2-0 on that occasion and Jagielka was hooked at half-time and he looks back now on that moment as the time when he became a man.
"That turned me from a boy to a man in a way. It was a strange game, really," he said.
"If you look back at the 45 minutes, five were bad and 40 were really good.
"I was happy with my performance but the main talking point was obviously my bad decision with the pass and then not getting back to tackle.
"Unfortunately, that's international football - if you make a mistake it's blown up and I didn't feel good after the game.
"But I would agree that it helped me to deal with the expectation of playing for your country and it took me on to the next level."