Slept very poorly last night - even my FitBit agrees - even though I was tired. Apart from maybe being a tiny bit feverish, I think it was due to sleeping position. Although, like most people, I move around a bit, lying on my left side seems to be my favoured sleeping position. As my left arm was still very tender, I stayed on my back or right side. So for anyone else contemplating getting vaccinated, when choosing which arm to use, think less about which hand you use for day-to-day stuff like writing, chopping wood, vanquishing enemies, etc, and more about sleeping.