Congrats mate - I would rate this as probably the best thread in my time here on The Org.
Anyway here goes :-
The birth of the twins (Alex & Jordan) - this was the first time I actually thought - "Christ ! Now I've got to be a grown-up !!"
Although I can't nail it down to a moment, one the biggest defining aspects of my life that definitely shaped the way I am today was the way that my parents supported my twists & turns of career choices during my teens & early twenties - no matter what I wanted to do they supported me & helped me as much as they could - I only hope that I can do the same for our boys - a very tough act to follow.
Finally accepting what various people had been telling me & my parents for some time - that I had (have [?]) a temper problem - once I did accept it I was able to start working to control it - if I hadn't God knows where I'd be today.