From everything I have read about addiction, it is far from that simple. One of the best examples are pain medicine like morphine. Give opioids to patients and some will form addiction to it and others will not, and the predictors for that are both genetic and environmental. It is not as simple as inject it into person X and now they are a slave to it. One way one can see this is in statistics in that long-term opioid use occurs in about 4% of people following their use for trauma or surgery-related pain.

It not at all certain that you would find it hard to stop if you suddenly decided to try smoking. There would naturally be a risk, but how high that risk is is a debated subject if you have none of the risk factors for addictions.