Mostly the amount of people. Yes, I've been to busy spots before (Paris, Disneyland), but those have been brief, a couple of days at most. In London, I was going on two weeks of constant interaction with thousands of people, and most of them coming from all countries of the world. It was like a whirlwind of every different language imaginable at times and 'twas quite overwhelming.
One afternoon, the friend I was staying with, Kim, suggested we take some time off from the hustle and bustle of city life and take a train over to Oxford. What a grand suggestion!
So away we went, adjusting to the endless pastures of the countryside and coming into the quaint town of Oxford.
Now I'm going to be really naive here and say that I thought that Oxford (the school) was a single building, like any university. Apparently, it's composed of like 30+ colleges scattered about the city. Since Kim and I had arrived there in late afternoon with not much time, we thought that a bus tour would be the most effective way to see as much as Oxford as we could.
And indeed that's what we did! We played tourist for the rest of the day, stopping off and taking photos of the beautiful school buildings, and stopping for tea next to The Alice and Wonderland Shop.
I can say that I felt smarter already just from being immersed in the rich history of Oxford. And it was just what we needed to escape for a bit.