Lol at hair being creepy!
(and I rarely lol)
If it's thick, shiny, swishy and glorious and most importantly, you really like it, then keep it. It is your hair, you get to decide how to have it.
If it's looking thinner at the ends in a damaged way then a really good trim of a couple of inches will make a huge difference to the condition.
I have bra strap length hair that is very thick but also shiny and healthy looking. I'd like a few layers putting back in it and maybe an inch or two off next time I get a cut. Just because I'm conscious of it being too overwhelming because of how thick it is.
There is a woman where I live who has hair my length. She's in her early 60s and it's grey strikes with white. She's the coolest, most confident looking woman. Really has style and looks amazing.
But on someone who dressed a bit frumpy and didn't bother with things like make up and grooming, long hair can look untidy and witchy, for want of a better word. Hard to explain what I mean really but my point is that there are a lot of things to factor in when deciding whether a hair style or length looks good or not but I don't think age is one of them. I certainly don't subscribe to the very old fashioned idea that women past a certain age shouldn't have long hair.