I couldn't believe it when my cousin (a CTO of a large company) was dying of multiple meyloma -- he actually was working from his hospital bed until a few weeks before he got an infection and died. That's probably exactly what he wanted, so godspeed. But, seeing that was enough to make me quit my job and try to keep things in perspective. Your customers and colleagues are can be extremely close and valuable, but your family and life you only get once.