Don't ever doubt yourself and your ideas.
You will fail if you don't believe in what you're doing. You need to convince investors of your passion and conviction towards your ideas. They need to believe in you, but first, you need to believe in yourself and your capabilities and your own ideas.
Did GM hesitate to compete with Ford?
Did Pepsi hesitate to compete with Coke?
Did LSD hesitate to... well you get my point.
