A few years ago I lent my body to the students of a colleague's occupational therapy course that dealt with extremities. Since I have one good arm and one that does less than little, it was a chance for them to "see and do" that they would normally not get at this level. Plus they could ask me pretty much anything. You can read about it in It's Touching.
I was asked about my medical history, of course, but also what I think I might have missed out on. I indicated my quality of life was just fine although I miss my guitars and golf. The most poignant thing I mentioned was that when my daughters were little, I was reluctant to toss or hold them in air. I still had plenty of strength at that time and could pick them up easily, but I was aware of what was unfolding and worried that at just the wrong moment my strength would fail. Bittersweet memory. I wish I still had the strength and sensation I had then.
Then something similar happened a couple of days ago. My only grandchild, who will turn one in a few days, has been visiting, and as one might expect, I've been busy playing with him. Lots of peekaboo in the past few days. (See: Update) My wife had risen early and took Finn downstairs. I followed a few minutes later having not seen him since the night before.
As I rounded the corner and came into view, Finn, in his best non-verbal way, raised both arms up in the air to say, "Pick me up, Grandpa." As expected, my spirits soared as my heart melted, but no matter how much I wanted to pick him up, I could not.