I smoked very rarely around age 18, but picked it up heavily from 19-20. I had to quit cold-turkey going into USMC boot camp. I was proud of myself and said that was it - no more!
But the night before we graduated we pulled a prank on the duty D.I. We thought it would be funny to blockade him into his office with seabags, and then yell out the greeting our firewatch used if the Officer of the Day came on deck.
You could hear him "thud" against the seabags, and then he went all kinds of crazy.

His revenge was walking around the squadbay for about an hour smoking and blowing it all over us, telling us how good it was and how we couldn't get our hands on one for another 12 hours or so.
I may not have been able to stay smoke-free, but that didn't help me any