Health,
Let’s take it really slowly, step by step.
1. Popa bar Abba asked when the best time to start smoking is.
2. You responded that in his case, the sooner the better, because that would benefit you. Presumably this is a joke – implying facetiously that you do not like Popa bar Abba and would like to see him get sick and die and thus out of your hair.
3. Meno does not think such jokes are appropriate coming from a self-described medical person. I cannot tell if he is joking back at you or not.