I have a commuting neighbor that I trade stories with too, although I never ride with him. He gets up way too early ;-)

It does have an addictive quality to it and I'm not sure I know exactly why. Part of it for me is that I like to tinker with things and bikes are a lot simpler than cars to tinker with. It's also cheaper to keep a spare so I can be working on one and still have another available to ride on.