Fear of failure
Fear of failure is the primary reason for us to not to do anything we dream. If we can control that fear and accept failure as the part of learning process, then I think all of us will do lot of more things in our life.
Cost of failure is also another important issue. Our society as of now values people with lot of money and it became a race for every one to become rich. There is less emphasis on if every one is doing what they want or not.
The change should come from us, we have to loose fear. I hope I am in right direction.