Gretchen Rubin alerted me to it, but of course we all know it. Getting enough sleep is a cornerstone of happiness. It is not only that lack of sleep makes me cranky and unproductive, it seems that lack of sleep actually interferes with self-regulation.
In my experience this is exactly the case. Lack of sleep means loss of will-power (which often leads to late nights, setting up a vicious circle.) It interferes with accuracy and speed. (The interesting study on Canadian road accident statistics on the days that summer time get switched on and off proves this.)
Earlier this year I slept well. This November I’m doing NaNoWriMo again, and it’s taking its toll on sleep. Although I’m not changing into a raging monster of unhappiness, I can feel that I need more energy to keep myself happy.