This is an old article, but a great one and worth mentioning. I came across it again after first reading a couple of years ago..
It is basically a light hearted look at how people become less important to you the “further away” they are from you, or rather the further away from your Monkey Sphere.
It reads as a joke but in all honesty I think the idea is well thought out and really interesting, and is well worth reading if only for the humour. Heres the link: