Just out of curiosity... at what point in your training did you realize that you made a mistake? What did you learn specifically in school and residency that made you become disenchanted with medicine... despite your experiences as a premed?
It is a long and complex story. i actually was a nontraditional student. Always wanted to be a doctor but life got in the way. Finally went back to med school at age 38. Loved being in med school, and matched into my #2 choice in general surgery. I thought life was going to be great!
After that, it was just a long, slow process of becoming dissatisfied. You don't realize how little control you have over things as a doctor. There is a lot of utterly stupid bureaucracy in medicine. And as the government tries to take control, more and more paperwork is required to prove you are meeting government guidelines.
Then there are the patients. They are getting harder to deal with- more demanding, more and more unreasonable expectations, more often with an in-your face confrontational attitude.
Ultimately, I rarely felt any sense of satisfaction from being a doctor. I still liked the intellectual aspects, and enjoyed being in conference discussing cases, but I wanted nothing to do with patients, or even a lot of nurses. I was tired of the pager intruding on my life. (at first it seems cool or exciitng when you get paged, but after a while I found that, at 2 am, I'd really rather just smash the pager into tiny bits)
As I was trying to get a handle on my dissatisfaction and figure out what to do, I read an article by a CT surgeon who had a heart attack himself and had to have surgery, and then slowed down his practice afterward. He described my feelings perfectly: society expects doctors to engage in "altruistic self destruction".
Ultimately, it came down to this: I had to meet everybody else's needs on demand (patients, nurses, attendings...) but nobody cared if my needs were or were not met. Nobody cared if I have time to eat, sleep or pee. When somebody decides they want something from me, they want it right now. If they don't get what they want when they want it, there are often complaints.
It doesn't matter if it's 8 pm and I've been in the OR all day now I have to do evening rounds. I stop in on pt 3 (of 15) and the room is packed with family members who have arrived from out of town, pt is several days post op, and the family bombards me for 30 min with questions (that I've already discussed with pt's spouse, but God forbid they talk to their own family). I have to smile and take it because if the family isn't happy they will go to administration and complain. So I leave the hospital at 9:30 pm, having missed out on my plans for the evening, and haven't eaten dinner. I'm dead dog tired- my back hurts, my knees hurt, my feet hurt. I have to arrive at hospital at 6 am and do it all over again. I have to prepare a talk for conference in 3 days. I don't have time to make anything healthy to eat,. So i shovel in some crappy food while spending a little time working on my presentation and then fall into bed exhausted. Get up at 5 to repeat the whole thing over again.
Ultimately the pain/benefit ratio wasn't worth it.
Maybe you won't find that these things bother you. Part of the problem with medicine is that you really don't get a good idea of what it is like, or if you can tolerate that reality, until you've invested so much money that it's too late. The student loan debt can be a huge trap. I find I recommend going though med school as cheap as possible, and avoiding debt as much as possible. You can't know now how things will play out. Nothing is worse than feeling trapped in a job/career you hate because of student loan debt.