As long as it's not dangerous

"The Cambridge History of English Literature was my constant companion, and it became infused with my cigarette smoke as I plodded through the pages. Almost all my women friends were smokers, some using cigarettes to affect a social ease and grace; others, more dependent upon them, becoming chain smokers. I myself was convinced that without a cigarette in my mouth I could neither study nor exercise any creativity. All unconscious of future revelations about nicotine, my mother would say to me, 'Why not-- as long as it's not dangerous.' And so I smoked my way through the Cambridge History of English Literature." --from Old Books, Rare Friends: Two Literary Sleuths and Their Shared Passion by Leona Rostenberg and Madeleine Stern (which is wonderful)