Huh? He's a second-year med student -- it's all but guaranteed he's going to make it, no matter what your interpretation of his "reasons". One ceratainly cannot give the same certainty of success for those in trading or money management.
Everything, abosolutely everythig except two things you have written, applies to some other fields as well: Phd. molecular biology, physics, chemistry, biochemistry, chemical physics, theoretical mathematics, and perhaps a few other fields. The two things that don't apply are: 1) if you are working on a Ph.D. in the hard sciences or theoretical mathematics, you don't pay to go to school, you get paid; 2) when you graduate, if you do, and after you do a post-doc for several years, you make less money. You work just as hard, if not harder, than a physician, and you have to use far more brain power, but you get paid less. But the work is fascinating and you don't have to poke a light pipe up anyone's rear end.. There is a reason these are called the "hard sciences"-- not to include theoretical math, which is the most intellectually challenging of all, but not a science. Medicine, as it is routinely practiced, is mostly a trade. The reason physicians can make so much money in this trade is two-fold: 1) medicine in the U.S. is a cartel where access is strictly controlled, as is the production of new M.D.'s, and 2) you are offering a service that can't be refused. These latter two things are not true of the "hard sciences".
Ok, so it's been over five years since your post. I haven't been through the whole thread. What did you do ?