Philippe Petit, the French high-wire artist who famously walked a tightrope between the Twin Towers in 1974, has a few thoughts for entrepreneurs:

You must not fall. When you lose your balance, resist for a long time before turning yourself toward the earth. Then jump. You must not force yourself to stay steady. You must move forward.

I don't have respect for people who walk on the wire with any kind of safety net. I don't really like the fact that if you fall you die, but it's part of what the wire is.

Of course when entrepreneurs fail we don't actually die, but there's no turning back once we step onto our 'wire'.

Life should be lived on the edge of life. You have to exercise rebellion: to refuse to tape yourself to rules, to refuse your own success, to refuse to repeat yourself, to see every day, every year, every idea as a true challenge – and then you are going to live your life on a tightrope.

Petit’s walk is captured in the movie Man on Wire, and here's a neat cartoon about Petit's impossible dream.