What's usually the biggest mental hurdle for hackers to transition into entrepreneurs? An understanding of their market? An empathy for users? How to tell a

What's usually the biggest mental hurdle for hackers to transition into entrepreneurs? An understanding of their market? An empathy for users? How to tell a compelling story about their product? Were past YC alumni who were more hacker-ish molded into entrepreneurs through YC, or did they already come in with such a mindset?