There is an important difference between self-esteem, which is a highly desirable trait, and vanity, which is considered a loathsome attribute.
Moshe, in his final days, beseeches the nation, “See I set before you today a blessing and a reproof.” This opening sentence of our Parashah can also be read, ”See the ‘I’ or ego is a blessing or a curse.”
To understand the concept of healthy self- esteem, we can look back to when we became a nation. At that time, we were told that we were chosen for a special mission. This selection was not for any special privileges but for an assignment which carried with it the expectation of a higher standard of performance. Behavior that would be tolerated in other societies would not be condoned.
This is essentially the concept of self-esteem to know one’s capabilities and to fulfill those responsibilities. One must always evaluate whether he/she has lived up to the expectations corresponding to his/her capabilities. This will never allow us to be satisfied with our achievements and think we have done enough.
Vanity is the opposite. It is the feeling that you have done so much that everyone should recognize and appreciate your greatness and accomplishments. The vain person will rest on his laurels and is hardly likely to think he has not done enough. In fact, he expects the whole world to pay him homage for having done so much.
Therefore the ‘I’ can be a blessing or a curse. Moshe, therefore, directs us to use it constructively.