Rav Schach (born 1898 CE, died 2001 CE) was a heavy smoker
in his younger years, before it was known how injurious smoking is to health.
After an operation, he asked his doctor if he could start smoking again.
The doctor said: �It would be better for you not to begin again.�
Rav Schach reacted: �If smoking is dangerous for my health,
even slightly, I will stop completely.�
He threw his cigarettes away and never smoked again.
SOURCE: condensed from HaRav Schach: Conversations (page 234) by Feldheim