Arnold Schwarzenegger wants to ''be useful'' to the world.

The 73-year-old actor, businessman, former politician and former bodybuilder has become a household name over the years, but has said his number one goal in life is to have made a difference to people's lives whilst also having a ''good time''.

Speaking about his outlook on life, he said: ''My father always said to me, 'Be useful'. To be useful, it's very important to do something that is bigger than you are, but have a good time at the same time. Smile, have a good time, have a positive attitude and see the glass that is half full rather than half empty.''

Arnold also doesn't take life too seriously, unless he's tackling a ''social'' issue which requires him to be serious.

He added: ''I never took myself too seriously, no matter what I did. I see some people in this industry and they look so unhappy all of the time. I want to say to them 'Smile, enjoy it - it could be your last chance!'

''I guess the only things I took seriously with the issues that I tackled on a social level. I joined the battle in convincing people to get off fossil few walls and into renewable energy, since we have an abundant amount of that. So those issues I took very seriously, but beyond that ... not really.''

And the 'Terminator' star believes he was able to make his career dreams a reality because he had a set ''vision'' of what he wanted his life to look like.

Speaking to Sorted magazine, he said: ''The vision I had of what I wanted to make of my life, has been a big part of the reason that I have achieved success and the type of success that I wanted. It's no fluke, and that has been enough.

''Sure, I was put on this earth to do something special. I guess if I hadn't succeeded, that I may have been the type of person my parents wanted me to be: A man who worked on the farm and had an army of kids like the Von Trapp family from 'The Sound of Music'!''