I was a social smoker from age 15 to 16 have i caused my self permanent irreversible damage?

Good 4U, no worries: Technically you will never know the answer to this. In medicine we deal in odds, the relative risk of developing lung cancer if you smoke for so many years is increased proportionally to how much you smoked. But someone who never smoked can also get lung cancer. One year adds little risk and each year that goes by brings your risk of any smoking related disease closer to someone who never smoked.

Hopefully not.: Although it may not affect every individual this way, it's felt that each cigarette you smoke in your lifetime reduces your life expectancy by seven minutes.