I have spent far too much time at institutions of higher learning, both as a student and as an instructor.
I have carried a variety of things in my daily outings. One thing that you haven't mentioned at all that I personally found invaluable was my laptop computer. I'm on my third right now, but it's falling apart and will likely be replaced within the next six months. Second or third priority right now. Replacing the furnace is first.
So, my list:
Laptop
pens, pencils, notebooks, sketchpad
calculator, when needed for maths classes (yes, you can do those functions in Excel, but we were supposed to use a calculator)
food for the day/dining card when I was on that program
water bottle
wallet with pocket money
textbooks
With all of that crap, I when I was a student, I didn't add a lot in the way of 'gear', since I was already humping a pack as it was. Pocketknife of some kind or other -- usually a slippie or SAK, sometimes a lockblade, sometimes a small fixed blade, and a small Arkansas stone. Maybe a lighter, but I don't smoke, so not usually. Couple of bandaids, a few tylenols.
Now, since I have a permanent desk, there's a lot less need for me to haul things around. I have a small PSK in the backpack, the laptop, a sketchpad and pens and pencils, a couple of knives.
Not much really. Desk has more stuff in it. Truck has even more.