James Nasmyth

In course of time the Brothers Cowper removed the manufacture of their printing machines from London, to Manchester. There they found skilled and energetic workmen, ready to carry their plans into effect.

If you're a filmmaker, and every time you finish a film, you just naturally go, 'Oh, I could have done so much better,' that's not much fun, is it, really? You might as well go pick another profession if that really is how you derive satisfaction from it.