When a person is saturated, when there is no margin, when there is no room for the unplanned, it takes so little to mess everything up.
It's kind of like filling your house with lines and lines of dominoes leaving no place to step, but then you really have to answer the phone which is across the room or you have to go to bathroom. The chances of knocking over even one domino in an urgent haste to get somewhere else are high - and you don't just knock down one domino.
Rest. Sabbath. There must be time to do nothing. There cannot be saturation.
The key to rest is learning the judicious use of the word, "No."
I could use some no.