All you need is ignorance and confidence and the success is sure. – Mark Twain
What you need is simple. All below are metaphorical, not physical
1) Cojones – Extra large
2) A Bulldog’s jaws – Once you grab on to something, you don’t quit.
3) Bulletproof vest – There’ll always be detractors, hanger oners, I-told-you-so’ers. Let it all bounce off.
4) A Dog neck cone – For focus. You only look back for lessons.
I’d add more, but with those 4, you can accomplish pretty much anything.