Jon, I think you are right about smoking being harder. It is something to do with with the nicotene content in the blood which is has to be got out of the system, it is also habit forming because people tend to smoke at certains times when stressed or just after a meal or for something to pass the time and it only takes one to undo the good from giving up and the chemicals added doesn't help. But it can be done. Irritability is one of the effects from quitting at first, but a mild fancy for a cigarette does happen from time to time no matter how many months have passed. Weight gain is another factor which might delay some people from quitting and because there are no outward signs like slurred speech as with alcohol, unless someone is smoking in a restricted place you can't really tell unless the person was actually having a heart attack or stroke, I don't think it is necessarily a genetic thing but some people defiinitely have more of an addictive side than others. Some people are able to work out the risks of drinking and can monitor it and others carry-on as they always have done not being sexist but some men still do like to call into a pub on the way home after work especially after a particularly hard day. Out of choice for me I would rather call into the pub around the corner for one drink than smoke my way through a packet of cigarettes ideally. The glass of wine or beer would be cheaper too.