When Did I Get So Old?

Suddenly, I am forced to admit, I find I can't do things I used to do. Or maybe not so suddenly. But still.
Dragging the 25 to 50 garden hoses Hubby had strung together (okay, maybe it was only 4, but it seemed like that many!) out near the manure spreader so I could spray out the bunny cages had me absolutely winded.
I no longer get excited when I hear the local amusement park is opening a new roller coaster.
I know better than to try to lift heavy boxes.
I find myself absolutely appalled by the way the world is going to heck in a hand-basket.
And don't get me started on the high school kids who loiter in the library! They have no better place to hang out than the library, where they scare the senior (and not so senior) citizens away?
Sometimes I get stiff when I sit and knit too long. Well, too long without moving anyway.
So when did I get so old?
Oh, I guess the memory is going. I do recall that dread birthday a couple weeks ago.
It must have hit me then.