There's almost no point posting this here. You will be inundated by responses from pre-meds who will all say, "Well, I'm not in med school yet, but!...." and then blather on about prestige, lots of money, "doctors just like to whine," blah, blah, blah, blah.
The point of these "depressing" opinions is NOT to necessarily dissuade you from medical school. It's to let you know what you may be getting yourself into.
Medicine, like any other field, is a spectrum. There is a huge variety of people who are in that field - some of them are very happy with great balanced lives, and others are extremely miserable and wish that they'd gotten a job as a McDonald's manager or something. THERE IS NO WAY TO TELL WHICH PART OF THE SPECTRUM YOU WILL BE ON. You might be one of the happy ones, you might be one of the miserable ones.
The point of these depressing opinions is to make sure that you understand that there are NO guarantees of happiness (or unhappiness) in medicine. Are you still willing to go into medical school, despite the very real risk that you might be one of the miserable ones? Have you asked yourself, HONESTLY, what you are doing to minimize the chance that you will be miserable as a physician?
Eh, maybe. Although not necessarily.
There are LOTS of "nontrads" who go to med school and HATE it. Even those who had fairly demanding careers in their previous lives. It all depends.
And I'd think that having a previous career would make some aspects of med school harder. Having had a salary before I came to med school, the lack of a monthly check was kind of a shock for a while.
I'll echo some of what smq said. And I'm coming from a perspective of having had a prior career before medicine. As a premed you often think you know more than you do. And you try to draw conclusions which aren't always based on the most grounded of facts. People aren't trying to dissuade you from going into medicine as much as telling you that medicine isn't what you probably think it is as a premed. You are hearing from folks who probably were just as wide eyed and optimistic as you a few years back, but ended up with a big plate full of something they were not expecting at all. So rather than all these posts of "I'm just a premed, but I think...", you probably should heed their warnings. Don't necessarily jump ship because of them, and don't downplay them as malcontents, but use this as a sense that maybe there's something around the bend that's not quite as smooth sailing. Assume that this poster could be you in a few years -- it very well could be.
Medicine is a great career for some people, and an awful career for others. The problem is that members of both of these groups find their way into med school each year. Adcoms do their best to try and weed down the latter group by asking pointed questions about "why medicine", etc. But inevitably you'll see the folks on SDN who lie about this but are still doing this path for all the wrong reasons. And yes there are many wrong reasons to go into medicine. First, the money. Money is quite good in medicine, but nothing like the net people in prior generations used to earn, and nothing like you might find on some of the jobsearch webs (cejka, etc). That's the kind of money you won't get anymore. Medicine is the only profession that has seen it's salaries decline against inflation over the past decade. It has also seen many of it's profitable activities made into unprofitable ones based on insurance company reimbursements. Some specialties have found the need to work longer and longer hours each year to earn approximately the same money they earned in prior years. So hours are up and salary is down. Still nice income, but you are going to work harder for less. So you are foolish if you are on this path for the money. It's too many years path for an income that isn't what it once was.
Next, the debt. This is the real reason doctors today aren't doing as well as prior generations. It's very difficult to do well when you are saddled with six digit debt coming out of residency. there are folks with a quarter of a million in debt, which is a lot more than most people can service without it making a dent in their lifestyle.
Next, the paperwork. Premeds don't get how much documentation is involved. You will be doing a ton of scut throughout your career. This can take up a huge part of your day. Writing daily progress notes, dictating discharge summaries, assorted other reporting requirements for billing. The amount of time you actually spend with patients isn't as great as it probably once was. This is now a business, and you are a paper pusher. Some premeds had a very different idea of what medicine was all about.
Rounding -- many premeds have a very different idea of what this involves. They don't appreciate how tedious it might be to walk around the hospital for 5+ hours, going from room to room presenting the patients to someone, who is going to pop his head in, and then go write a note. Some specialties are all about the rounding.
Finally, the whole "helping people" thing. You will get very jaded when the only real helping you often find yourself doing is giving a drug seeker the IV dilaudid that was the real reason he faked a chest pain and got admitted. It's easy to get jaded in medicine because you will see a ton of people coming to the doctor for reasons other than illness, be it drug seeking, or looking for that "get out of work" note, or trying to bilk an insurance company. Some are legit, but it's easy to get jaded by the human condition.
So you have to know what you are getting into, and know yourself, and know that this isn't going to be the daily cake and icecream some premeds seem to think. You will work long hours, be and feel underpaid, have to deal with a lot of paper, a lot of painful rounding, a lot of undesirable patients. For some, the negatives outweigh the positives. For others, those few positives in the day keep you going. But only you know which type of person you are. And the real reasons you are on this path. Which isn't for everyone.