Find that man. Make him your friend. Whenever you have an idea, invite him for coffee.
He will say no. He will show you all the challenges, problems and reasons it cannot work. This might demotivate you, irritate you and frustrate you. If it does, it means something he said is probably right.
Therein lies the benefit. Exposing your ideas to people who will evaluate it with harsh and unrelenting criticism is far more valuable than seeking the company of yes men. It’s painful and draining, but also invaluable.
Accepting the input of the man who says no is comparable to hacking the failures of all the yes men combined. It is immensely powerful to those who are willing to embrace rejection. Your vulnerability to scrutiny is what will set you free.
If no-one challenges your thinking or conclusions it’s time to find someone who will.
You will be better for it.
PS. When you appreciate the value of this man, you will discover that he says no less often, it just feels that way.