... so that's where they were hiding.
By which you might surmise that I made it to the Y, and went swimming, and it was good. Ok, it was also pitiful, because I managed 4 lengths (2 breaststroke, one backstroke, one sculling and kicking on my back) before my body went "Ok, done now." But that's better than nothing, and next time I go, I can aim for 6 or 8 lengths. (And I then went and trod water for 10 minutes, which is also not nothing.)
After which, there was sitting in the whirlpool for a bit. (And, I also have access to a steam room and a sauna there and look forward to trying them out.) I can already feel the post-exercise stiffness in the back of my shoulders, but in a "Hey, worked out these muscles" not in a "agonising pain" sort of way.
( A digression into my swimming history )