Job presentation on a major life achievement?

I have been recalled to a third job interview next week and I have been asked do do a presentation on a major life achievement which has to last 15 minutes. I am considering talking about my degree, however im unsure? As im still quite young I do not have that many major life achievements as yet!

Does anyone have any ideas?

Thanks for you time!!

Mark

Try and get one that is as relevant to the role as possible.