What is the worst thing about being an entrepreneur?

Having everyone that you talk to think that they know more about startups, your market or your technology then you do. Through various networking events I have meet people who have never started a company or were an early employee at a startup try to explain that I don't understand what it takes for a startup to succeed. I have been an early employee at 4 startups (not including the two I was a co-founder) of which two of them had minorly successful exits. But I obviously don’t know what I am doing because I don’t have their degree or attend the right conferences.

There's no map to what you should do nor anyone to give you directions. A lot of people will offer guidance and it's your (hard) job to make the most out of the (often times conflicting) advice you get.

You feel like being alone on a island!

Not knowing whether the task you're working on at a given moment builds real value for the company or is a complete waste of time. Momentum and morale matter in a start-up. When you realize the project you've been working on for weeks (or even months) is the wrong direction for the company or just doesn't work, it can be deflating. Even for creative-minded and entrepreneurial people, it can be difficult to accept the amount of creative waste that occurs in most start-ups. Moreover, the stress of achieving some measurable success, whether driven by investor demands or your own personal desires, doesn't help matters.

Worst thing: When you wake up each morning, you never know what is going to happen.