What's the best thing you have ever done in your teenage life?

My greatest achievement in teenage life was learning to walk after an horrific motorcycle accident. I was 14 and my older brother left his keys at home one night when he went to the pub. Knowing he wouldn't be back until early hours I took his 600cc motorcycle for a joyride and it ended very badly. My parent were told the odds of me ever walking again were 95% not in my favour. took me till i was 17 to walk again (after 11 operations and rigorous physio) but I did it. Aged 20 just six years after being told I wouldn't walk again I completed the London Marathon (all be it just short of 4.5 hours).

So although nothing spectacular, for me that has been my greatest achievement in life not just my teens..