Starting a business definitely requires learning to persist in doing the right thing during days without positive feedback.

The most exhausting part of entrepreneurship is working your hardest but not hearing any response.
Working for someone else provides immediate feedback, but entrepreneurship involves a counter-human delay.
Delayed gratification is like digging a well: the first 99 meters are full of mud, no applause, no money coming in, and even you start to doubt yourself.
But as long as the logic of making money is correct, keep fighting to the end.