Michael J. Fox's kids have never seen 'Back to the Future'.

The 54-year-old actor is best known for playing Marty McFly in the 1985 time-travelling adventure and though the film is still hugely popular today, his children Sam, 26, Aquinnah and Schuyler, 20, and 13-year-old Esme - who he has with wife Tracy Pollan - are not among its fans.

He said: ''Ironically, for a time-travelling movie, there was a timelessness about it. Kids now like it. Though my kids haven't watched it. Or, if they have, they haven't told me.''

And Michael - who suffers from Parkinson's disease - admitted he was even considering giving up acting before he landed the role in the movie.

Speaking at a fan convention in London at the weekend, he said: ''I was thinking of working on the fish dock or joining the military like my dad. Then suddenly I found myself on a set with Steven Spielberg.

''[I was] very overwhelmed by the whole experience.

''The nadir and the peak of my career happened at the same time.''

Filming didn't always run smoothly on the movie though, as the actor was repeatedly struck by the doors of the iconic gull-winged DeLorean car which his character drove through space and time.

He joked: ''I wish I had a gag reel of every time I got whacked by that car door.

''[The reel] would be like 30 seconds of 'whack, whack!' ''