Well, it varies obviously.
im also 55 and can no longer run up & downstairs.
i can bend over to get things from a low shelf, but i cant crouch down.
nope to Attic
Pretty much overnight my knees just became unbearably painful to kneel on & bend and an accident meant I had to have my entire shoulder replaced.
My elbow joints hurt like fuck & my hips.
You're never too young to do what you can to protect/strengthen then.
@InThePinkScarf
youre not too young to practice the getting up off the floor in several different ways, plenty of reels on it & if I was your age & fitness I'd start doing wall Pilates/yoga or whatever.
that flexibility, strength & fitness you have naturally now & take for granted will not always be there unless you work on it.
I was probably late 40's when it started going downhill, 52 ish when it was more obvious.
I don't expect you to listen, I didn't. I cant be an example, let me be a lesson.