Maybe I can help those of you folks that mourn your decades passing. Could sharing my perspective maybe ease the pain? I don't know but let's give it a try.
I remember a time when looking my very best mattered a lot to me. I even remember when I stopped getting a lot of attention for being a young single female. That took getting used to, I won't lie but I knew there was a lesson there. Life having it's seasons is a beautiful thing and should not be seen as just getting old. Here's my take.
In your twenties you explored. You stretched your wings and tried to learn to be in the world. Before that the reality of your being was shaped by being under your parents wing or being pushed out of their wing because they felt you were in the way. Maybe your guardianship was left to adults other than your parents. Either way, you did not have a lot of chances to exercise personal choice. So, your twenties were really where you got to build those muscles. You made mistakes. You got some stuff right. You learned some lessons. At this point your body was made for a twenties lifestyle.
Your thirties you knew a lot more and probably became a little more settled. If you'd always been settled, maybe you decided to stretch your wings and be in the world because, until this point, you'd not had the chance. Your looks started to change a little. If you jumped into the air maybe you didn't jump as high and when you did, the landing felt harder than it had in the past. You could still do all the things you did before but you noticed that your body wouldn't always be the same. You'd experienced life a bit and you could look back and see all the lessons people had offered you, only now you got them and you understood what they wanted you to see then but couldn't for lack of experience. During this time you really started to build on calm and meaning in your life. The small shifts in your appearance and physical abilities made it easier to calm and find meaning. Life became less about appearances and more about substance.
Your forties came and your body and looks continued to change. You had lived. You were probably more you at this point than you had been since you were born of your mother. You could let the appearance and shifts in your body make you stagnate but you didn't have to. You could still do all you could before, although a little slower but because you were a little slower you paid more attention to the details because there was no rush. The fact that your looks were changing shouldn't have been of importance to you because you once had that and now you have this. It's been that way every decade. "You once had that and now you have this." There is no need to mourn what passed because this decade was the opportunity to not worry over the trivial things like you did in your twenties. Being adorable had ran it's course but you knew enough by now to make a happy life. Your beauty didn't leave you, it was just repackaged in a container that was less about the container and more about the contents of the container.
Every decade in the process of aging makes you more present. As you cast away your childish ways of being, you make room to be where now takes place. If you can be in the now instead of mourning the past, you can begin to see the beauty in life that you might have missed out on because you focused on things that were trivial when you were young. Looking at the long game, wouldn't you rather be forever fabulous because you finally get it or temporarily youthful looking and inexperienced again?
I cannot tell you about 50 but if it's more of 40 but smoother as life has been with each decade, I'll take it, buff it up, shine it and make it my own. I couldn't always do that in my 20's but I'm equipped to do it now, as are you. You've never been more awesome.