Not having personal goals in one's life is detrimental to a person.
A person without personal goals is merely existing. He or she is not living his or her life to the fullest.
When one does not have personal goals, he or she is not driven to achieve more than what he or she currently have. He or she will not discover new skills nor hone the existing skills he or she has.
Having no personal goal will hinder an individual from reaching his or her true potential as a human being.