Actually I agree with Maya it's fun looking back on what we wore a couple of decades ago-- even if I cringe a bit. I think that experimenting with fashion and trends is what helps you define a style, or look, that you enjoy wearing. And that continues even when you get labeled a senior citizen.
What I think is even more interesting about this thread is the assumption that there is a huge gap between being classic or being trendy/edgy. I suspect that most of us incorporate both elements into our style at one point or another but what translates as edgy for a senior citizen is probably much different that what is edgy for a 25 year old. Tucking my jeans into my boots is my edgy-- and it does get a backhanded compliment from my son as well as being quite practical. Is it also a classic look when worn with a jacket and scarf? Maybe, since I've seen pictures of Jackie O sporting a very similar look.
One of the best parts of being younger is having the willingness to try more extreme looks-- like my oh-so-fashionable 60s red-checked pantsuit. I laugh at it now, but it was my edgy, trendy look when I was 19 (along with those skyscraper platform shoes). My point was that, without knowing it, some of the things I wore in my 20s were the start of my classic style, although I certainly wouldn't have thought so at the time. Other looks were fun and trendy, but definitely look dated and strange now.
To me, a classic style is about developing a look that endures because it fits the personality, shape, and preferences of the individual. I laugh at that red-checked pantsuit, but it helped me define my style to the point where I can purchase something today knowing that it will look as good on me a few years from now as it does today. But classic style is not frozen in time nor should it depend on specific items. I think that classic needs to be constantly refreshed by experimenting, and selectively adopting, trends and new ideas. That is where Angie and YLF come in-- to help me find my new classics.