The importance of being unrealistic

Yes, in order to achieve unrealistic goals, you have to be willing to attempt them. But there is survivorship bias at work here. Of course the people who've succeeded in their unrealistic goals will tout the importance of never giving up. You won't ever hear from the people who failed.

I think you (the general you, not the author in particular) have to come to terms with the fact that unrealistic goals are unrealistic for a reason, and that failure is the most likely outcome. You have to find failing at what you want more desirable than succeeding at something you don't want.

I think the part about perfecting your skill, instead of relying solely on talent, is probably where most people will find success in their lives.

In my opinion the most important skill is philosophy, I think someone once asked "To be X or !X?" Without philosophy we have nothing, no science or math. If greatness is doing the best we possibly can at everything we do then that's "great" for us personally but does it make other's lives great as well? It is one thing to be of the highest possible skill level, or in other words "great", at something like programming but what if your goal is to make everyone who touches your work from testers to line managers live's easier? Wouldn't you be perceived as "great" regardless of your skills as a programmer? Will Smith seems like such a great guy his energy just radiates from everything he says and does and his work ethic is also inspiring. But a performing artist's role is probably more altruistic than someone in a technical role where the altruistic outcomes are less obvious. Start with philosophy my friends.