But I don't really understand why normal women do it. I mean, surely anyone you know knows how old you are and is used to what you look like. So do you do it for strangers?
I will tell you why.
OP, let me guess. You were (and no doubt are) a very attractive woman. You got a lot of comments in your twenties, thirties about how attractive you are, your gorgeous face, your beautiful body. You were always aware of men admiring your looks, and women too. And the gradual loss of that attention has hit you hard and you are trying to get it back.
When I was in my twenties, I would walk in to a meeting, a restaurant, get on the tube, and I would often be aware of people looking at me. I was told by men that I was dating that I was beautiful. I looked in the mirror and I could see that I was very attractive. My skin, hair, body, were a picture of health. It was assumed I was a model a few times.
In my thirties and now with young children, and I feel and look the difference. I feel a bit down about it. ATM, using creams etc, but absolutely not averse to Botox later. When your have had 'it', it is bloody difficult to come to terms with losing 'it'