Wolves' on-loan Chelsea ace believes scrapping for survival turns boys into men - something the top stars do not experience.
Defender Mancienne, 22, aims to get stuck into Everton this weekend to keep his temporary club on the right road to Premier League safety.
The England Under-21 centre-half said: "I am maturing and playing first-team football. It's a massive thing for me.
"And an experience like this has helped me grow up. A relegation fight is something players like JT haven't experienced and it is helping me to mature.
"When I play against Everton on Saturday I'll be stronger for this."