Hollywood, California

I recently got an invitation from Robert De Niro to spend the day on the set of his new movie 'Little Fockers.' Needless to say, it was a pretty cool day. Apart from Mr De Niro (known affectionately as 'Bob' to his inner circle) it was a star studded cast filming that day, including Ben Stiller, Owen Wilson and Barbra Streisand.

The first thing that strikes you on a movie set of this size, is how many people there are. There were well over 200 crew, actors and extras, all working as an amazing team. Their attention to detail is unbelievable. In between takes, lookalikes of the main stars go and stand in the positions that the stars are standing in during filming. Each of the main actors has their own make up person continually (as in every few minutes) updating their make up for continuity. And yes, because we were outside in the sun, Barbra Streisand had her own person to hold an umbrella all day to keep her shaded. Good for her.

But apart from having a lot of fun, the one thing I learned from the day - and it was a big lesson - was the extent to which the stars were willing to work away - graft away - at their art.

Obviously, comparisons to  a 'proper job' are ridiculous - and no, I'm not making any comparison to Robert De Niro working away on a movie set and a nurse or doctor working an 18 hour shift in casualty.

But I would make a comparison between Robert De Niro or Barbra Streisand's work ethic - and the work ethic of many 'successful' people that I know, maybe even you and me.

First, they spent the entire day filming a total of approximately one minute of the movie. One minute. And they told me that's about average. So two hundred people and an entire day's filming of multiple takes, for just one minute of the finished product.

The scene they spent the day filming involved Robert De Niro laying on the ground (I won't give away the story) Ben Stiller running up to him to check on him and Barbra Streisand in the background offering to give him a massage to revive him.

They filmed that scene again and again and again and again, all day, from every angle imaginable. In every tone of voice imaginable. With the tiniest variations that they could choose from when editing. I don't know how many times I stood at the side and watched De Niro go into character for just a few seconds filming. But it was absolutely fascinating. Each time Ben Stiller ran over to him, he would warm up, off camera, by doing press ups, so that he would be out of breath when he arrived.

Again, most people would make the comparison to a typical job and talk about how these stars have got it easy. That would be correct but I don't think that's the point. I was interested in watching these veteran stars from the perspective of pure excellence. An excellence that many desire but few are willing to take the steps necessary to achieve.

In a world of reality TV shows producing overnight 'stars' I wondered how many would be willing to lie on the ground all day, in exactly the same position, for a few seconds of movie. And then do something similar, every day, for 70 days. You and I see these actors at awards ceremonies and on TV shows but we don't see the sheer hard work they put in, day in and day out for their art.

These people make it their life mission to become masters at what they do. It just so happens it's an art that bring them fame and fortune. But I don't think 'Bob' spent that day on the ground for fame and fortune. I think he did it because if you're committed to mastery, you have no choice. Contrast that to the typical Entrepreneur's reluctance to master almost anything and the blueprint for success in any field starts to become very clear.

I'm trying to sell you something here. I'm trying to sell you the idea of mastery. It gives you many things. One of the less important is an ability to dominate a field. But above all, I think that mastery gives you fulfillment. And it doesn't have to just come from your work. Maybe your mastery is parenting. Or painting. Or making people feel good. Who cares. Just don't spend your life dabbling.