I smoke
I enjoy it as I rarely drink excessively any more (shocking, especially for a student) as in I'm about half of the reccomended weekly intake of alcohol for an adult, and it's something becoming suprisingly social (chatting to fellow smokers outside etc). Don't smoke a huge amount, but that first cigarette of the day with a cup of tea before work feels great
Don't smoke inside in my shared house or at my parents home out of respect for others and I don't really care what people do aslong as it only affects them, e.g. smoking in a beer garden.