Is 21 too old to be a doctor?

Its virtualy impossible to be a doctor at the young age of 21. You have to have years of college and training to be a qualified doctor. If you are asking if 21 is too old to start training as a doctor, the answer is no. The oldest person I knew was a woman who started her college training at the age of 34having married young, had three children AND recovered from a hemorrhagic stroke.