I want to add to my earlier post.
First, please do not make any judgments about life as a military doctor until you are well into ROTC or even serving on active duty (BTW, there is nothing wrong with serving out your obligation in the Infantry, then separating to attend medical school, and then re-entering active duty in the Medical Corps). If you are a junior in high-school right now, you simply do not have the exposure to this life to make any kind of informed judgment about this. You do not need to plan that far ahead at this point. Sure, you can work toward that path, but you can always diverge if you have to. In my case, I entered ROTC with the aim of becoming a military physician but quickly became fascinated with the prospect of becoming an Infantry officer. While on active duty, things changed for me, and eventually, I went to law school and combined my science degree to become an intellectual property lawyer. Who knew?
Let me now give you a glimpse of being a military physician from the perspective of a DS who's father was a military physician.
One thing you are ultimately going to have to decide is what objectives are you seeking as a physician generally. You don't need to decide that now and probably should not until med school or later. Some folks are perfectly happy making Hollywood movie stars look younger. Others want to help sick children in Africa. Others want to serve in the military. These are aspects of becoming a physician that no one here on SAF can guide you on -- it has to come within yourself. You will, however, have experiences in the military that only a military physician will experience.
My father has had a considerable amount of job satisfaction in the military. He is especially proud of having saved the lives of many of our brave Soldiers after they were torn apart during in a firefight. He served in the middle of things from Vietnam to Desert Storm. For example, my father recounted a story where he had just finished saving the life of a US Soldier in the operating room and, after he was finished, he had to turn to the other operating table to save the life of the Vietcong soldier who had just tried to kill that US Soldier. He did say that this experience was kind of weird, but military physicians are bound by the Hippocratic Oath like any other physician. My father also recalls joking around with helicopter ambulance pilots in the hospital cafeteria while they waited for their next run, only to find these same pilots on his operating table a few hours later when things didn't go well on the next evacuation. Today, in Iraq and Afghanistan, military doctors are busy treating our Soldiers, our enemies, and the children who are affected by those conflicts. They are just as much proud members of our military as anyone else who serves.
When I was young, I remember my mother looking nervously out the window for the Army staff car to pull up after learning from the television that the Da Nang Army Hospital had just been inadvertently pounded by an American B-52 bomber (by that time, she was already used to the shelling that the hospital had received from the Vietcong). Similarly, in 1989, things were just as unsettling for my mother when she woke up one morning to learn that the United States had just invaded Panama (my father was on an unaccompanied tour at the Army hospital in Panama at the time, and I was on active duty as well). This is the life that my father chose, and he is very proud to have been a career military physician.
The other thing about being a military physician is that you may be called upon to serve in "other people's wars," while the rest of the military is not engaged in combat. During "Black September" (September 1970), when Syria invaded Jordan, my father was chief of surgery at Heidelberg Army Hospital in Germany. The US military decided to send two surgeons to help out the Jordanians (not as US military, but as American Red Cross surgeons because of the political issues involved with sending US military members to that conflict). My father was instructed to pick two people from his surgical staff to provide surgical support during that conflict, but he decided to go himself along with his deputy.
My father came home that morning and told my mother that he had to be on a plane in two hours to go to the Middle East. The Syrians and the PLO got very mad at this, so they placed a contract out on the lives of the families of these two American doctors who went to Jordan. The Army then called my mother to advise her that the Red Brigade terrorist organization had agreed to assume that contract with the intention of murdering me, my mother, and my sisters. We were not evacuated to the United States, but we had a bunch of men in civilian clothes in our apartment and circled around our military housing building for about a month (I'm not sure which unit that was who was assigned to protect us). Eventually, the conflict in Jordan ended, and nothing happened. But it sure was weird when my friends came over to play and were greeted with Uzi machine guns at the door.
I am not recounting all this to spook you. But it seems that there aren't too many Hollywood movies that give you the glimpse of what it truly means to be a military physican, and what it can mean to the lives of your future wife/husband and children (I know this is FAR from your thoughts right now, but if you're planning that far ahead, I might as well throw that in). As you do the ROTC thing, you may find that some may consider you as "less military" because you want to pursue a dream of becoming a physician. Just shrug that off, because you will be just as much a part of the military as any other active duty servicemember.
And if you ultimately decide the military is not for you, there are plenty of opportunities for you to be a very productive contributor to our society.
Again, you do not have to make "life choices" right now. That time will come when you are about to complete your service obligation from ROTC or from an SA and have to decide whether to remain on active duty or not. You have at least 10 years to make that decision.
Good luck.