I have a 4yr old boy and a 2yr old girl. I smoke cigars, I drink and I brew beer. They ask questions and I answer honestly. When the 4yr old has asked to try the cigar I said "When you are 18 you can". When he asked me why I told him because his body has to be big like mine (at which he points and laughs at my belly) and that just like driving, the law saw you have to be a certain age or the police will come and get you. Would this conversation work with an older kid, probably not but I am just learning as I go. My parents drank and smoked cigars in front of me and I always understood that I couldn't until I was older.
By the way Remo, I haven't forgotten about you