The desire to do it and the perseverance to keep on at it. As Jason Nesmith says, “Never give up, never surrender!”
Or “King Kong aint got nothing on me!”, “Thats not a knife, this is a knife”, “Life is like a box of chocolates” and other such useful movie quotes.
So keep going, no matter what and do what you love best. Or as one more movie quote would say, “Run Forrest, RUN!”