One Day You Fly, The Next You Eat Dirt

Day 84, Thursday March 26, 12.30pm: Funny thing, my body. Or is it my head?
Yesterday I got on the gym bike and I absolutely flew. My brother Roger had just set a new world record for 20 minutes on the gym bike and I massacred my personal best to pip it.
Jan says it's because I'm competitive. Me, competitive? I used to be, but now my joints make strange noises when I bend down to pick up 7-Year-Old's discarded clothes and I take afternoon naps. Me, competitive? Roger, years younger and lither, longer legs and without pacemaker, could regain the world record within days if he wanted to.
No, it's not that. I just felt good and I pedalled and I didn't seem to get tired. So, enjoying the sensation, I pedalled even faster. And there you have it.
So today I went for my swimming lesson, apparently determined to beat my eight consecutive lengths of crawl. And I gave up. After five and a half. I spluttered to a stop. I just felt lousy and I seemed to get tired and, not enjoying the sensation one little bit, I headed for the side of the pool.
Was it my body or was it my head? I don't know. Funny things, bodies and heads. One day you fly, the next you eat dirt. Or, more accurately, swallow more chlorinated water than is good for you.