I notice that in the past year or so I've changed my riding style as well.
For me it depends who I'm with. I ride differently depending on the group and that dictates the speed of the ride. When I'm out with a certain group of boys it's balls to the wall and I'll admit I get a thrill from the speed of that. But I've noticed that I hardly go out to those rides anymore.
I prefer to meander along at my own pace now. It's not that I can't ride at those speeds, it's not that I can't keep up....it's that I don't necessarily want to. I'll rail in the corners but when it comes to straights I just can't be bothered anymore.
Doesn't help that 50 over the speed limit up here is an automatic racing ticket and license suspension.