When I was studying for Step 1 a few years ago, I studied 18 hours a day, every day, including weekends, for 6 straight weeks. I would wake up at 7AM, be in library by 8AM, take an hour break at 12PM to work out and eat lunch, study from 1PM - 2AM with 15 minute break for dinner, rinse and repeat. During that time my fiancee would bring her dinner to eat with me during the 15 minute break, because that was the only time she saw me. I was always coming home after she went to bed, and leaving in the morning before she woke up. The rest of my med school years really weren't much better (I was studying 14 hours a day on average); this is just the example of how it was like at my busiest.
I wasn't studying that hard because I wanted to eventually get into a competitive specialty that would pay me lots of money and allow me to relax. I studied that hard because I felt that it was our duty as med students to study as hard as we can and learn as much as we can. I always got infuriated when fellow students would say something like, "Oh I'm just studying 6 hours a day, I just want to go into family med so I don't need to do better than average" or "I'm not focusing on that topic, because I hear it's low-yield for this exam" or "Hey can you quickly go over the key points of the material for our final exam tomorrow? I didn't start studying until 2 days ago and I'm now really behind." I find that kind of attitude offensive because even if I had my mind set to go into a non-competitive specialty, I would have studied as hard as I could because I don't think behavior like what I described is right for our future patients. Frankly, I always felt that people who approached their studies like that shouldn't be allowed to become doctors. We should always strive to be the best - not for the sake of getting good grades, but because we should be the best students of medicine that we can be.
Now, did I feel really guilty about how I treated my fiancee during those 6 weeks (and really, during all of my med school years)? Absolutely. I know she was miserable because I never had time for her. I never had time to visit her family, I never went out with her and her friends, and I always made her go to her friends' weddings by herself. Hell, we never even had a real wedding of our own (just signed some papers and drank champagne in our apartment living room). She wanted to attend a very good graduate school in a different state but chose to go to a lesser school near me (although with the amount of quality time we actually got to spend together, it probably wouldn't have been that much different if she had gone out of state). I know her friends have asked her why she's even with me when I never have time to hang out with her. Do I hope that one day when I'm a full-fledged doctor, I get to be in a job that allows me to take good care of patients while at the same time spending quality time with my wife, and be able to pay her back for all she's sacrificed for me? Absolutely. Does that make me a bad unethical doctor, who cares only about money and doesn't give a crap about how patients feel? Absolutely NOT.