Matthew 5:28 says "But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart." Does this apply to other things? If I had a desire to smoke and drink, but I actually don't do it, does it means that I had already smoked and drank? Do I call myself a smoker and a drinker?
"Let no one say when he is tempted, "I am tempted by God"; for God cannot be tempted by evil, nor does He Himself tempt anyone. But each one is tempted when he is drawn away by his own desires and enticed. Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death. Do not be deceived, my beloved brethren" (James 1:13-16).
I've notice that people have a hard time distinguishing between a desire, a temptation, and lust.
A desire is what you want at the moment. It doesn't necessarily have to be bad. I might be hungry, tired, or wanting a chance to relax.
Temptation is when Satan offers us what we want, but to get it we have to do something wrong. It ought to be clear that in order to be tempted, we must consider what is being offered. Being tempted is not a sin. Jesus was tempted, yet he did not sin. "For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin" (Hebrews 4:15).
Lust is when we decide we want what Satan offers, but at the moment we don't have a opportunity to act on it. Using your example, if at the time someone handed you a cigarette or a beer, would you have smoked or drank?
Lust isn't the same as committing the actual sin. A man guilty of lusting after a woman hasn't committed adultery yet. Jesus charged that he has committed adultery in his heart. The point is that sin doesn't start with the actual action, it starts with the lusts of the heart. "And He said, "What comes out of a man, that defiles a man. For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, thefts, covetousness, wickedness, deceit, lewdness, an evil eye, blasphemy, pride, foolishness. All these evil things come from within and defile a man"" (Mark 7:20-23).
The problem is that some people excuse lust as harmless because it hasn't been acted upon. What we see is that lust is corrosive. It eats away at a person's spirit making him more likely to give in to the actual sin. Even when the sin isn't committed, the defilement of the person's spirit is itself a sin. The battle cannot come in resisting the chance to do a sin, but must come earlier in rejecting the thoughts about doing a sin.
So, you might be thirsty and tempted to quench that thirst with a beer. You can rejected it, or dwell on it wishing you really had a can available. The lust for a beer isn't drunkenness, but it will make you susceptible to indulging in drinking if the opportunity arises. The lust for alcohol isn't drunkenness, but the drunkard begins his sin when he starts lusting for alcohol.