Charlie Sheen

As England manager I always felt we needed an extra man in midfield to retain the ball, but that was more as an attacking ploy to help create opportunities. It came from my experience playing international football in a 4-4-2 and spending half my time chasing the ball.

Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap.