what are the barriers to success?
In my opinion, the most important ones are lack of self confidence, I mean when you don't believe in yourself and your potentials, and not having great goals in life
Sadly, in the world we have created, another important barrier to success (and I'm talking about economic and social success, since the success is a very relative concept) is to be subject to ethics.
Don't you think that this fear that you mention is due to being afraid of failure?
I think fear of failure is one of the important barriers to success .
If you believe that we don't really got a chance to "choose", you'll see that in the eyes of an observer there is neither a barrier nor even an option for us. Our life just goes the way it's supposed to.
Even though, it doesn't mean that we shouldn't do anything. Our ignorance gives us the opportunity to surprise ourselves by picking options that we are supposed to pick. So, as you mentioned, self-esteem, motivation, determination and whatnot will help us to find our way to our very predictable future!