One of the ingredients that made Cheers work so well was the great ensemble of actors we had. That's the case with any good series.

We need to start looking at having a way of managing the whole ecosystem, because you can't pick away at it piece by piece, you have to truly start being coordinated and managing our resources as a system. We haven't gotten to that point yet.

I don't know if I went to the gym, [but] Woody [Harrelson] was 24, and at that point I was like 37, which is when you realize you're no longer 24. So in walked Woody, who was instantly great, but offstage, it was [all] testosterone. We'll arm-wrestle. I still have, like, tendinitis in my elbow. Woody cleaned everybody's clock in everything. Then we got less physical and went to chess, and he whipped our asses with chess.

The biggest danger we face is overfishing. We literally could fish out our oceans, some scientists believe, in the next 40, 50, 60 years. We are fishing out the top of the food chain, and it's pretty crucial because about 200 million people depend on fish and fishing for their livelihood, and about a billion people, mostly in poorer countries, depend on fish for their protein. So this is a big problem. Good news is, it's fixable.

At the time, my 6-year-old kept thinking my character's name was "Sam Alone," which is kind of brilliant. The funny came out of Sam's sad core: the alcoholic, the sex addict, the person who thinks he's God's gift.

It's not enough to have good thoughts for the world. You must get out there! It is also really important that each person realise their own worth. If you don't think you're good enough, how can you turn around and help save the world?

I feel very strongly that you can't just beat people up anymore; you have to work hand in hand and find ways to compromise, and get big business involved, because it won't happen otherwise.