This is on the whole a very cheering thread. Thanks, OP.
I've stopped dyeing my hair and can already tell that once I've got through the "illicit lovechild of a fox and a badger" stage, I'll be far happier, not wasting time and energy on something that looked OK for about 10 days and then involved 2-3 weeks wondering how long I could hang on till I did it again. I love the way it grows in random streaks, sometimes blending in with the rest, sometimes standing out and catching the light.
When I was about 30, I watched a very good friend give a brilliant paper at a conference and I remember idly admiring how wise her reading glasses made her look. I'm not at the reading glasses stage yet, but am not bothered at the prospect, thanks to her.
Now that my DC don't need me so much, I walk 5.5km every day. I can't run because my joints are dodgy, but I walk fast and feel so much better for it - quietly toned, strong and healthy. Six weeks ago, I began taking exactly the same photo every day at the end of the path, and am enjoying seeing tiny changes in skies, seasons and colours. It's a small but satisfying pleasure, and the hour all to myself is a luxury that I didn't have time for when the DC were younger. Then I come home, all chilled and energised and slot back into the evening/morning routine.
I feel and therefore look miles better for that daily walk.
Every grey hair and every line I have is a reminder that I managed to get out of a deeply toxic marriage, a bit dented but very much stronger and less naïve.
I wouldn't erase any of them.