That's the entrepreneur's dilemma. How do you posses enough passion and confidence to make it through the tough times but known when to call it quits.

It's the single most difficult part of entrepreneurship. It actually gets harder the further you are along the path.

If you give up too early on all your ideas the decision has marginal difficulty. The more you're invested the more difficult it is to decide to throw in the towel.

So the more you progress as an entrepreneur the more difficult it becomes.