Steve Jobs explains the rules for success
You need a lot of passion for what you’re doing because its so hard. Without passion, any rational person would give up. So if you’re not having fun doing it, if you don’t absolutely love it, you’re going to give up. And that’s what happens to most people, actually.
If you look at the ones that ended up being successful in the eyes of society, often times its the ones who love what they do, so they could persevere when it got really tough. And the ones that didn’t love it, quit. Because they’re sane, right? Who would put up with this stuff if you don’t love it? So its a lot of hard work and its a lot of worrying constantly. If you don’t love it, you’re going to fail.