What’s the biggest obstacle you think young founders face?

While building StarterSky I realised mentorship is one of the biggest challenges for young founders and would be great to have someone to talk to. But starting a business comes with so many hurdles, which one do you think is the biggest roadblock? 1. Mentorship 2. Funding 3. Balancing studying/working with a startup 4. 4.Building a network? 5. 5. Any others? Let me know.