He has an effortless, boundless, unassailable cool, and yet is either unaware of it or sufficiently unimpressed by it so as to be nonetheless totally inviting, approachable and easy (not just fun) to be around, which of course only adds to that coolness. "Addicting" would not be too strong a word to describe experiencing it; you can't believe how great it makes you feel, every time you're around it you want just-a-little-more of it than you get, and when you're not around it you're thinking about it.