-My father is a doctor, I must continue with tradition

-Doctors make a lot of money

-I like the intelectual challenge

-Its a profession of service, there is nothing better than serving another human being

-It has great flexibility (you can work anywhere in the world)

-I just can´t imagine myself doing anything else

-I want to make a better world (maybe cure cancer)

Whatever the reason it has to be a strong motivator, to keep you going with days with no sleep, very little contact with your own family, 4 yrs for undergraduate, another 4 for MD and then other 4-7 or even 8 yrs (eg. neurosurgery in UW) as a student.