For me, is their any good reason to not be aware of your role in life? It's not like the world is revolving around you. Wouldn't it be a shame for a person like you to not give back to the people you love and to the world too? Even a three months old baby has a role to play. Because we are all important to God. Therefore there are only disadvantages. Being ignorant is one. Don't just sit there, if you were given a chance to live then move and do good deeds. Stop procrastinating and act now. Another disadvantage, you wouldn't be happy with your life because you don't get to do the good things you wanted to do. Having to do something for the greater good should be your ultimate role in life.
good luck :)