Thank you, posters, for providing a good therapy session here, for both my child and me. We deal with existential questions and contemplation misery at my house too.

My DS10, at age 6, got teary-eyed while hugging me and said he does that sometimes because he knows he won't always be able to hug me. He collapsed in tears after reading his preschool handprint poem, which he found in a keepsake box, because he won't ever be that little again. I'm the one who's supposed to be crying over that, not him! (And I do, of course.) He struggles with simple decisions, as another poster mentioned here, because he cannot bear the loss of the other opportunity, or loss of time to do one thing that comes with choosing another. He struggles to enjoy his pets because he cannot ever forget that someday they will die too, and he is living that misery, mourning them before they are gone. There is the old "Nothing we do matters if we die anyway" but also sometimes "I guess if we only get one chance, we should enjoy it" and the vacillating back and forth creates its own emotional yo-yo. So much good advice here, and it helps a lot to know that we are not alone in this struggle.