Remember- you are looking at multiple years of school and each year that schedule will change. Not to mention housing and possibly even roommates. The cost of bird ownership is also VERY HIGH--- the cage and bird are a lot, but the vet bills, toys, food etc, all add up very quickly (especially for a macaw whose toys are about $40 each and last a few days to a week MAX).
Birds don't understand why you suddenly have to spend less time with them etc, and they are designed to fly miles and miles a day....so making them pets to begin with is already highly unnatural. Think about the fact that this bird may bond with your roommate more closely than it does with you..I mean, you will be living together,but not for 80 years. I am not saying they can't adjust, but when my ex and I broke up, my bird became depressed due to his absence. These are all things to consider...There is no explaining anything to a parrot---they LOVE routine and they tend to hate change, but they are deeply sensitive and in the wild, they would always be within contact distance of their flock. This is their normal...it is not our normal.
I really wish you would wait until you were through with school. Having been through many years of school myself (and having toyed with the idea of getting one sooner) I am SO glad I waited (even though at the time, I would have thought it doable...)
You will have internships, classes, etc ---you can't throw off a bird's schedule like that. I have to be home by 4 at the latest to let mine out and feed her dinner. If I am late, she gets anxious (it is difficult to explain this to a boss, and it is something I have had to do many times over). My bird has a set bedtime (they need them, just like kids). Similarly, sleeping in is going to become a thing of the past when you have a bird with a 12 hour sleep requirement and life obligations (you can't just leave them covered past that time while you catch up on sleep). Mine is up daily at roughly 5am because of my work schedule and her need for 12 hours (sometimes she gets up even earlier). If they go to bed at 5, they should wake up around 5. In college, something like 9-9 might work for a short time, but is unrealistic if you have to be at work by 7-8am when you have a job etc. You still have to have time to play with your bird (at least 4 hours out of the cage with active interaction for many of those). Life changes SO much between the start of college and end of college and you will likely be VERY short on cash for all of college. There is literally NO WAY you could work, attend classes and keep a happy bird without losing your mind completely. Being a student and owning a bird is nearly impossible , working and owning a bird is very difficult, but doing both and owning a bird (especially a large bird) is not a good idea.
It sounds simple enough, but trust me when I say this:
If you would find parenting a 3-year-old to 4-year old human child with special needs to be difficult at this juncture in your life, then consider the fact that parrots can be more challenging than humans for a variety of reasons, AND they are terribly expensive, while requiring a TON of time, effort, consistency, and attention to their medical needs (Is there an avian certified vet in your area? Exotics vets are NOT the same.)..Also, if you adopt a baby parrot (esp a macaw), you are looking at a few years of deceptively sweet/quiet behavior before you get the full attitude/volume level of an adult bird. They change a lot at puberty and although puberty is very rough, adult birds will always be more willful/stubborn/bossy/assertive than their baby selves (in fact, babies often push away from those they love most at adulthood). Imagine if you (currently) and compare yourself to how you felt about things when you were 1 (you can't even remember, but you get the point I hope).
Macaws live past 80 in many circumstances and never grow up (unlike human children). You also must consider your future romantic partners and any potential children of your own (birds take a huge chunk of your freedom away, and you owe it to them to be there). This can cause turmoil in human-to-human relationships. They also require tremendous attention and make tremendous noise (it is their nature as flock animals). What happens if "little Johnny" (fictitious future child) is napping and the bird starts screaming? What happens if it bites your significant other repeatedly out of jealously, or even your future kid, requiring hospital visits? What happens if the bird starts plucking out all of its feathers or even carving away at its skin because you are unable to spend the time with it necessary to keep it healthy/happy? Have you considered all of these possibilities?
Travel will also be pretty much a no-go (yes- people do it, but if you can't bring your bird, you are looking at caging it for days (unnatural) and potentially exposing it to asymptomatic disease carriers at a boarding facility)). Also, unlike human children, birds are extremely suspicious of new people (often aggressive/seriously fearful if you are not there too) and so hiring a friend to drop by and do your bird work will not make your bird feel any better about the fact that your are gone...and without a bond, they will likely be unable to handle the bird or even return it to its cage.
SO many college students re-home their birds within a year or 2 of getting them because they simply didn't comprehend the level of work/commitment required. It happens all of the time.
As a future vet, you will have plenty of opportunities to take on unwanted birds within your practice (it happens all the time) so please wait until you have the financial and lifestyle stability conducive to raising your own children before considering a bird (especially a macaw).