Thanks for your advice DO. At 34, with a 15 year career now behind me, I tend to judge every opportunity in terms relative to that experience. I am well aware that medicine carries its share of unpleasant burdens and, of course, now two years down this path after three years of considering it, I've probably got about as good a picture as I'm going to get before actually stepping foot in med school
Having engaged in a career that I did not find fascinating and discovering that it was, in fact, not fascinating, at least I am closer to the mark now.
As far as the passion/fascination debate goes, I'm not so sure the difference in meaning between those terms is great enough to be meaningful when they are used by different people. I would never describe myself as passionate, as I don't have deep emotional reactions that I would describe as passion. So, perhaps I am not equipped with what other people describe as passion, or perhaps my concept of fascination is equivalent to your concept of passion.
Again, judged relative to my previous career, the opportunity is there. I certainly did not mean to imply that it is effortless, or costless, or possible without total rearrangement of one's life, but then, I wouldn't have come to this point in my life if any of those considerations were major deterrents.
To find work at my level in my previous job, I had to commute away from my community during the week. In addition, my community has a perennial dearth of doctors. Judged by those factors, I would have a heck of a lot more involvement in my community.
I figure it this way: I did 15 years in a career that offered me great opportunities that largely bored me and left me rather culturally adrift. Six more years of school and I'll be 40. After residency, I might be 44-45. If I felt stale in my circumstances after 15 years once, it could happen again. What would I do, bored at the age of 60? Well, plenty of opportunities exist - change of specialty, change of location (potentially even change of country) and patient profile, move to research, move to teaching, etc. That is a whole dimension of opportunity that did not exist for me before. Of course, as you point out, none of these changes are easy, but I don't demand ease - just opportunity.
On a 15 year cycle, I can only get bored a few more times before I kick the bucket.