I have perhaps one friend that I've known more than 15 years. Part of it is that I seem to be bad at keeping friends, and also because I spent a decade moving around a lot and just lost touch with people.

Paul Allen and Bill Gates were friends from early teenage years until the 60s, until death. Through so much change in the world, much of it instigated by them. Through becoming some of the richest, most powerful people on the planet and then turning into philanthropists together. Nearly half a century.

I literally cannot imagine the emotions Gates has to be going through as he writes this note. My heart goes out to him as much as Allen's family.