Actually, as long as my health remains reasonable, I love (yes, love) - or, rather, I am very comfortable with being middle-aged.
Psychologically, and mentally, I think I always felt middle-aged, even as a child, and now that my physical age had caught up with my mental temperament and disposition, I feel a lot more comfortable.
The world is not designed for introverted, intensely intellectual, serious, young women.
I loathed being young, was very bad at it, - yes, the boundless and bottomless energy was nice, but little else appealed - for I generally felt awkward, and alienated, and bored by my peers. "Fun-loving?" "Playful?" "Parties?" Even those very terms evoke a mad desire to produce a parabola of puke.
My twenties were better than my teens, my thirties a lot better than my twenties, my forties and once I reached the half century - and plus, - an awful lot better still.