At the age of 119, your body is probably not very strong, and while normally one smoke won’t kill anyone, if a 119-year old who has never smoked smarts smoking, I would imagine it could be quite dangerous. It’s probably safer to start at 70 or 75 than at 119 (especially since the average life span for men is only around 79, I think).
If you really have to smoke, you should probably do what one person I know does – he only smokes once a week, on Motzei Shabbos, because he says you can’t get addicted from smoking once a week.
But best of course is not to smoke at all!