Why are startups hard?

Probably different reasons for many people. Timing is hard for some people (family, job, school...) The uncertainty is hard to cope with for others. Money issues make it hard too. It's easy to doubt yourself when things don't go right the first, third, and 8th time you've tried it.

The question that entrepreneurs need to settle before starting is,

"1/10th of all businesses fail. Would you go through 9 failures just to get that one big success?" Maybe your 10th business is a hit and the first 9 were just a test for you.

In another view - from my generation's superhero: "Being an entrepreneur is like eating glass and staring into the abyss of death."

School is blamed way too much. I went to highschool on both coasts of the USA (Massachussets and Washington,) in relatively rich areas of the state/country, so we're not talking about inner-city here. Free-thinkers at these schools were not beaten down or broken, at a minimum they were treated the same as everyone else, at a maximum they were handed opportunities from connections, local companies, clubs, etc. Even IF schools mercilessly beat down free-thinking, these are not the people that would become entrepreneurs. You have to be able to think away from the norm to get into this scene in the first place. These kinds of people probably aren't affected that much by school's instruction in this sense.