Add one more to your young'uns club. DH and I have been together since we were teenagers. He went to med school right out of undergrad (we were both 21). We got engaged during his first year. I moved in with him from a nearby city at the end of his first year and started my graduate education. We got married during his fourth year. DH is now finishing his intern year.
I don't think being the SO of a med student or resident is necessarily a loney journey. We've been very fortunate that DH picks up this medicine-stuff very easily (which doesn't mean he didn't put serious hours into studying for step 1) but throughout med school and intern year, we have made time so that we get at least 2 hours/day together. He planned his study schedule ahead of time and weekends that were right before tests or now if he has call on a Saturday, I will plan a trip out of town to go visit friends or family or a day out with the girls.
I read almost everything I could about specialties before DH was finished with his first year. From the very beginning, I let him know that I would really like him to consider lifestyle in his selection of specialty. I caught quite a bit of flack for this but I know him better than anyone. He likes having time to do things that he likes outside of medicine. He likes visit our college friends. And if there is work to do, especially if it impacts patient care (which it always does) he will go the extra mile and work work work even though he is tired or hungry (which is just another reason why I love him but also why I knew he shouldn't be doing cards/surg/etc.) This isn't right for everyone, but DH was able to combine his desire for patient care and like of outpatient setting with a career that will allow for some free time.
As we are finishing the intern year (sometime during 3rd year, I stared viewing med school/residency interviews/and now internship as something we are both doing), this is probably the worst it will be. DH's new mantra is "only one more month (of floors)." In all honesty, intern year hasn't been too bad. We will be moving in June across the country for the rest of his residency so when DH has a weekend on call, I go to visit friends and family out of state that I won't see as often next year. He also chose a program that has a night float system so even though the hours can be long, he gets to come home every night. When he is not in the hospital, he is 100% not in the hospital. I know next year will be more reading and studying (since he will be in his specialty then), but it is a return of 2 day weekends and the start of home call.
We love our life. I feel very fortunate that DH gets to do what he is meant to. I think one of the advantages of being young through this process is that we have been there every step of the way (studying for the mcat, applying for med school, during classroom, clinicals, choosing a residency, residency interviews, etc). DH frequently tells me can't imagine doing it alone. Med school and choosing a residency made us examine what was important to us (with sometimes limited time, what do we value most and what can we do without) which has positively affected our relationship.
So to answer your question, DH wanted to do well. I wanted him to do well. But keeping balance in his life was his priority. There are things, such as step 1 or his core rotations, that we knew doing well would me greater choice in specialty which meant balance for the rest of our lives. When he was studying for his step 1, I was teaching a course for the first time so I stayed busy. During his surgery rotation, I had the opportunity to go on vacation with my parents. This past year, he had to work on Thanksgiving (first major holiday since we've been married), I knew I would get loney spending the entire day by myself so we had our own Thanksgiving on Tuesday and I went to my parents house and spent the actual day with them. So, med school and residency have had their impacts but I'm sure there would be other challenges if he were working.
Best of luck to you!