The midfielder endured a difficult six months with the Toon before returning to Marseille on-loan ahead of signing permanently.
He told Canal Football Club: "My failure at Newcastle? It served me.
"I had my first failure at OM then I went to Newcastle. I had a second failure. I told myself that I had no choice. I changed some things in my habits, in the preparation of matches with a physical trainer and a mental trainer.
"After that, you are no longer the same person on the ground."