Downloading and using hacks? Hmm let me see, too young to remember, probably since 2007~2008, but I only hacked on a game called Warrock then, when it was still new and cool, and since then I've only hacked on games witch I had lost interest in playing as they were meant to be.
Funny fact from back of those days about AC bypassing would be my view on those things back then: As I was probably like 10~11 years old back then, I didn't care wether the hacks for warrock were detected or not, I simply downloaded the one with the best features, hid it into a random named folder on desktop and renamed it and thought "Voila, now punkbuster wont find it, ou yeah", always was a big surprise later to find out hack either not working or recivig a ban

You learn from your mistakes, as they say
As of creating my own hacks, I'd say 01/01/2012, ofcourse I had been messing around with CE before and abit in visual studio but thats when it got serious. I'd say I've adapted everything pretty well, could've done better/faster though