Self Esteem always ends up being conditional and it can be ruined by conditions we or others place on us. When we put conditions on ourselves such as what we can achieve, how much money we have, how will look or how witty we are we will always set ourselves up for failure eventually.
Would you hold another person in lower esteem because they were not smart, witty or rich? If no why would you hold yourself to those standards?
The idea that some outside event will improve your self esteem like better grade of some other arbitrary measure of success is a very egoistic and foolish notion.