Even in this global internet age, your main friends at any given moment in time are still decided almost entirely by geography. While you're at school it will be your school friends, at university it will be your uni friends, and after you leave, you won't keep in touch with either of them that often, certainly not as much as you think you will - unless you happen to live in the same town as them.
There are very, very few people you will remain close friends with once you have moved to different cities. I have about 4 oldish friends I still see on a semi-regular basis who don't currently live in the same city as I do, and that's probably more than most people have. A friendship that actually lasts 10+ years is pretty rare frankly.