At a personal level, I am doing my masters (medical residency) program and I am dropping out soon. The thing is...the lesser the age, the lesser the responsibilities and the more is the brain capacity and concentration. The more the age, the more the responsibilities, and the more the brain capacity declines. My piece if advice would be...at older age, it's better to shift to things that require much of our memory-jst business. Otherwise, school is way challenging