There is a simple and very logic explanation as to why I cannot sleep well when I am ill. Being sick means I tire easily, and that in turn makes me rest a lot during the day. Sitting and napping are not things that encourages a good night sleep. I now realise that I need a significant dose of daily activities such as cleaning, cooking, gardening, etc. in order to put my body in low energy mode.
Since recovering from this flu two days ago, I have gradually return to being my squirrelly self. The moving about has at last allowed me to have my usual pass-out type of sleep. I slept well last night. Oh how I have missed my deep, glorious, dream-filled sleep!