I started out when I was maybe 11 years old.. See, a friend had a Yamaha DT80- beautiful machine! It looked like a full-size street bike/motorcycle (turn signals, horn, lights, side panels, etc.) only it was 80cc and kid sized. It was also "dual-sport", so I guess it was a scrambler- high pipe, high front fender, street knobbies.. One look at this thing, and I *HAD* to get a bike. Eventually I got one, although not as fancy as my friend's. Mine was a Z50. This was around 1984 or so, and the little Z50 must have been either late 60's or 70's vintage. No lights, no rear suspension. It did have front suspension, and a front and rear brake, and I abused the living tar outta that thing! Other friends had: an XR80, KX80, XL100, DS80.. And my little Z50. I'd jump it, wheelie it, two-up ride it, climb steep hills with it, etc. It never looked any worse for the wear! It never broke, and I sold it looking the same as I got it a few years later, when I upgraded to a '77 IT-175 Yamaha.
My first steetbike was a Kawasaki EX-500, which was also a great bike, despite the fact that most friends that had other bikes would talk smack about it. It was really quick and nimble, and it's a wonder I didn't get myself into trouble on it- although I did manage to slide the front end in a corner once! I later let a buddy learn to ride on the EX, and he returned that favor by letting me ride his CBR600 Hurricane when he bought his first bike. Then I moved on to a '79 CB750F, an '81 CB750F, and a '82CB900F. Sold all of them, and now own my '77 CB550K.