Tom Hardy says having kids made him "get [his] act together" and stop thinking about himself.
The 'Legend' actor - who has struggled with alcohol and drug addiction in the past and once reportedly said he would've sold his mother "for a rock of crack" cocaine - changed his life after the birth of his son Louis, seven, who he has with ex-girlfriend Rachael Speed.
Tom - who also has a three-month-old child with wife Charlotte Riley - said: "I wouldn't say it saved my life, but it definitely changed my life.
"That was when the penny dropped that there was no longer very much time for me to think about myself any more - about what I might like to do or who I want to be - because there is somebody now on the planet who really needs me to get my act together and focus on something that is more important than me.
"And when I go home, I am not Tommy the actor, I am Tommy the dad, largely because my children aren't allowed to watch any of my films yet. My older son really wants to watch 'Mad Max', but I've told him that he can't - he's got to watch the Harry Potter films first!"
During his younger years, Tom struggled with drugs and started taking hallucinogens at the age of 13, while three years later he was taking crack cocaine and drinking alcohol.
The star has had a very busy few years, filming latest Hollywood blockbuster 'The Revenant', starring as notorious gangsters, twins Ronnie and Reggie Kray, in 'Legend' and also starred as Max Rockatansky in 'Mad Max: Fury Road', and he admits all the work has left him "quite tired".
He added to the Daily Mail newspaper: "I'm a very lucky boy!
"I have had a lot of opportunities to do some very interesting movies lately, so I've been working very hard. The downside is that I am quite tired right now."