Medical school was one of the best things to ever happen to me. Believe it or not, there really are people out there who enjoy all four years!!!
I absolutely LOVED the pre-clinical years. It helped that I freaking obsessed over Biochemistry, Anatomy, Microbiology and Physiology. I loved it so much, I went back to TA those courses! Life is easier than most people whine about during those years. Your SOLE goal is learn and study. How much easier can that be? I was even able to hold down a small part time job with Kaplan (I worked about 10hrs/week). Yes it is competitive, yes you are surrounded by high achievers and yes the material is high in volume and difficult to master. But, honestly, you don't have any real responsibilities. Most of my classmates were able to pass and still have a life outside of school.
The clinical years were also phenomenal. I found that it tends to be easier for those who have held jobs before. The ones that struggled the most were those who were socially awkward or didn't realized that no one gave a crap what their opinion was. This was definitely the most difficult year in medical school but like any job, there are rules. The number one rule in third year? Be easy to get along with. Why? Your evaluations are subjective. There is nothing you can do about it and complaining won't change anything. So learn the rules and play the game. Bring your personality. There is nothing worse than being around a rude/awkward/lazy medical student (I have witnessed this as a resident). My poor friends who came from these liberal arts schools where all their opinions matter; what a culture shock for them!
It sounds awful doesn't it? Well, remember, you get to LEARN MEDICINE. Finally, after all that studying, you put what you learned to use in a clinical setting. You realize the subtleties of medicine they can't teach in a classroom. You learn that while it is great that someone can memorize the entire differential list to a symptom, really, you need the most likely disease states to work with. You learn to do procedures. You learn to interact with patients. You learn to interact with nurses and other support staff. I think some people fail to realize that third year is NOT just about learning the medicine, it is about learning how to work in a medical profession. It is about how to communicate with your colleagues. It is about learning how to gather evidence (history and physical), putting a treatment course into action (assessment and plan) and if needed, providing an argument for others to help you (consults, nursing orders).
So do I regret medical school? Heck no! I would seriously do it all over again if I absolutely had to (though I would like to avoid that scenario as I value my time). Could I do ANYTHING else? Absolutely not. There is so much more to just being a doctor. You could choose that route if you want to: getting your degree, doing your residency and working for the weekend. There is nothing wrong with that. But you can choose to do other things like research, teaching, writing, politics, consulting etc.
I am saying this as a senior resident nearing the end of my residency. I do not think I am a rare entity. I wholeheartedly believe there are plenty others who think similarly. Misery breeds complaints and complaints need to be heard which turn into threads. Who wants to read a post about how great someone's day was? Boring! So don't be dishearted premeds and soon to be MS1s. Life in medicine is what you make of it. You will not love everything about medical school or even the practice of medicine. But there will be specific pockets that you will fit well in. Find them and embrace it. You will find that it is not all despair and frustration as toted in this forum.