Interesting thread and discussion going on here. I, and my significant other would call my "pipey-ing" a hobby. Its more involved than just eating or drinking to me. I feel like it's more like homebrewing, which I also enjoy. If it was something I just did, like buying a six pack or smoking a cigarette I would say its neither a hobby or a lifestyle, but I personally enjoy learning and reading more, understanding the deeper aspects of it like burn temps and chemistry behind it, learning about tobacco's and how they grow and what makes them different, as well as the history and other things like that. While I love the simple act of smoking too, it's those other things which to me makes it a hobby.