I have never really felt my age but that may have something to do with never fitting in with my peers. When I was younger, teens and early 20's, folks thought I was older. By the time I hit my 30's folks thought I was younger. I am also not very good at recognizing age in others. The only thing that makes me feel like a 30 something is the grey hairs and assorted ailments. I guess I have just never been able to nail down my existence, felt so untethered to society at large, not for lack of trying. I also tend to miss out on the big life moments. No prom, no college, no mortgage, no mariage etc. I haven't cellebrated my birthday in years.
I have always been aware of missing out but... well, only how I behave in the future can change that, the past is what it is.
I'm actually considering celebrating my birthday this year. It feels like I finally have a life worthy of such things.