How tired you will be and how unembarrassed you will become about taking naps in public. I’m talking lectures, the library, computer rooms, and in my building (Sir Alexander Fleming Building or SAF as we affectionately term it) there are lots of grotty looking sofas on the ground floor. If you study biology or medicine I almost guarantee that will you attempt to nap on the SAF sofas before your time at Imperial is out.
How much you will just not care about your appearance. I mean, everyone likes to make an effort for certain events and occasions, but whereas at home I would never go to college without having washed my hair and thought about my outfit, I am pretty happy here to just put on anything and go.