Older docs telling them "medicine ain't what it used to be" and try to convince them to avoid it. They ask me my opinion and my response is always: "Do you want to be a doctor?"

If being a doctor (or a dentist or engineer or whatever) is what makes you happy and are passionate about, then I don't think all those other reasons for NOT doing it really matter as much. Are there things about my job that I wish I could change? Sure! But at the end of the day, if you find your actually day-to-day work meaningful and rewarding, then I can put up with all that other stuff.

If your motivation for becoming a doctor is to make money, make your parents proud, or whatever, you are going to be disappointed and frustrated with your career and everything you sacrificed to get there.

I love my job. I have a hard time picturing myself doing anything else. I have plenty of colleagues who are miserable doing the exact same job and probably would have been much happier somewhere else.