Osvaldo says he can be "horrible".
"I always want to change and think happiness must be elsewhere. This is the first time I've had two consecutive seasons in one club," he said.
"There are days when I feel sad and would like to be a different person, to lose myself in the world. I miss Argentina and my childhood. I'd like to be an adolescent again.
"I am a bit of a lunatic. One day I feel strong, the other useless. I fight, I score, I react, but I do everything to excess. I was forced to grow up, but there's a part of me that rejects the idea of growing up. I make pointless fouls, but at that moment they seem right."
Osvaldo has received nine red cards in six seasons and will sit out a three-match Coppa Italia ban for elbowing an Atalanta opponent.
"It's true, I have a horrible personality. But I kind of like being like this. I always miss something in life, especially my home in Argentina."