Yes, I too am a naturally quick mover and I too have noticed that I have slowed down a bit in some respects and need to do so with regards to some other things.
I don't think our brains automatically slow us down to the speed our bodies would prefer. My 65 year old body has made it quite plain that I am no longer 20, but my mind is not really interested in processing this information!
Apparently I still want to believe I can mow three large lawns in a day, or walk a mile and a half carrying a backpack with between 12 and 15 kilos of shopping in it.
Thankfully my legs and back still agree with this optimistic outlook on life, but are insisting on being allowed to take part at a slightly slower pace.
And yes, I agree clothes pegs are not what they were: now-a-days they seem to be fiddly, slow things to use, which they never were when we were young. The times they are a .changing!
I've noticed DH and I complaining about all the things we thought so ridiculous when our parents and before them our grandparents went on about them.