Why don't you ask that person how much luck was involved.
They were smart in how they quit, not lucky
they decided to quit and they did it.
They weren't silly and non protective of their goal.
They didn't let temptation lead them back to smoking by going and getting drunk.
They took it one day at a time and grew even stronger.
Life evened out for them because they weren't dependent upon nor consumed by the habit.
They realized they need not fear life without a cigarette
I wish you honesty and perserverence, not luck