When one starts practicing yoga sincerely and correctly, one’s mind becomes more subtle and focussed. When this happens one comes to know oneself in a different way. Generally, one comes to know what deficiencies one has and this makes one sad in a way.
But, one should understand two things:
a) one has to make positive usage of this information so that deficiencies can be removed one by one as possible. This will later give one joy of accomplishment that is incomparable with the ordinary material achievements.
b) one should know that one has deficiencies in some areas, but one also may have great capabilities in some other areas. One should use those capabilities towards further improvements or achievements. Also, knowing the plusses makes helps keep the sorrow of knowing the minuses down to minimum.