Sometimes we have spiritual desires that exceed our natural abilities. This can cause a great emotional crisis in our lives when we appreciate the gap between our desires and the reality of our capabilities.
When you compare yourself to great people and realize that you just don't have the stuff it takes to reach such heights, it can be PAINFUL.
The solution is not to minimize one's strivings and desires but rather to find a balance between being satisfied with what you have and at the same time constantly striving for more. This way you will remain happy while at the same time aspiring for more.