I found a new ME/CFS metaphor. As a child I enjoyed this swimming pool with a small section that had a stream. The water was pushing you forward. That's the extreme good day. That's the: wow, what's happening here, I can do this activity??
The rest of my days are normal swimming, but as someone who's out of shape. Can swim 5 minutes... 10 minutes... then I need a rest. Or if I refuse to rest the swimming gets slower and uncoordinated.
What my sister and I used to do with the stream was to try to swim it backwards. We went against the easy direction, making it hard for ourselves. My sister says she managed to swim the whole 'river' once, when I was not watching. I could only do it by clinging to the sides of the pool. That's today.
Everything takes a lot, too much effort. I have to go downstairs soon and see what food options I have in the freezer, but for now that seems really impossible. Everything that involves moving any limb is just.. too hard.