My son told me a joke from school and I laughed half a second too late

Dear Delyara, He noticed. That was the part that stung. Not because he said anything, but because I could tell from his face that my laugh had come from effort before it came from instinct. I was there in the room. I heard the joke. I answered appropriately. But I was slightly delayed in my own life, and children always know. Afterward I felt guilty in that familiar, ordinary maternal way. Not because I failed him terribly. Just because I saw the gap between the mother I want to be in the moment and the mother I sometimes become when the week has already taken too much out of me before evening. I’m trying to be kinder about that gap. But it hurts every time I see it.