[krav]

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.