The 57-year-old star shot to fame in 1977 with his Oscar nominated performance in ‘Saturday Night Fever’ and despite the hard work involved with making movies, he still gets excited about new roles over thirty years later.

He told OK magazine: “I can’t imagine ever getting tired of it, I grew up with it. After a while it’s hard work more than it’s a creative thing. I know I’d probably be shot for saying that sometimes, but you have to be there to know it.”

One of the reasons John loves to act is to it helps him work off excess energy, and he admitted he gets restless when he’s not working.

He explained: “There’s a bit of a mischievous child in me and it does get me in trouble on sets. But age seems gives people respect for their elders, so you get away with it a little more.

"I was a classic child of the ‘60’s, filled with sugar highs and crashes. I was rumbustious and creative and I would channel that energy into performing a lot.

"If I am not able to perform, watch out, because I am filled with the spirit of the play."