I was the same way when I started smoking in high school in the 90s. “I’ll be fine if I quit before I’m 30.” We were under no illusions. We called them death sticks like plenty of other people who smoked. My wife used to say “glad I’m not pregnant” when she saw the pregnancy warning. Thankfully, we both quit many years ago and have not apparently suffered any long-term repercussions, but who knows in 20 or 30 years?
And that was something we knew killed lots of people.