Taking care of something, a plant, a pet, a little sister, gives a day weight it didn’t have before.

Responsibility for a living thing changes the structure of a day. Something outside you depends on you showing up, which turns an aimless afternoon into one with a fixed point in it. It is not the size of the task that does this. It is that somebody or something would notice if you did not.

Take on one small ongoing responsibility and do it without being reminded. Water something, walk something, read to a younger kid twice a week. Keep it for a month before deciding whether it helped, since the effect comes from the repetition.