Founding a company is hard. Most of it isn't smooth. You'll have to make very hard decisions. You have to fire a few people. Therefore, if you don't believe in your mission, giving up is easy. The majority of founders give up. But the best founders don't give up.
I feel that the best companies are started not because the founder wanted a company but because the founder wanted to change the world... If you decide you want to found a company, you maybe start to develop your first idea. And hire lots of workers.