And as he feels himself falling asleep he has an insight he believes is important, which he hopes he will remember in the morning, although it is one of those thoughts that seldom survive translation to the language of daylight hours: knowing that whatever plenty befalls them together or separately in the future, they will become more and more intimate with loss as the years accumulate, friends dying or slipping away undramatically into the crowded past, memory itself finally flickering and growing treacherous toward the end; knowing that even the children who may be in the future will eventually school them in the pain of growth and separation, as their own parents and mentors die off and leave them alone in the world, shivering at the dark threshold.
(Click to show. Warning: May contain spoilers.)