We fought over sleep schedule.
She wanted to be an early riser. Sleeping late left her sluggish, feeling she'd lost the hours of her best productivity.
My rhythm was to be up till dawn, sleep till 1pm. The hours from midnight to daylight were my best work time, when I was sharpest and most energetic. I would sometimes stay up all night for class after breakfast.
I did not expect the depth of her frustration, or recognize the damage it did to our life together.