I said to Jeslyn today, "when you miss someone who's in the same room as you, that's an epic kind of miss", to which she responded with this quote from Milan Kundera's book, Identity:

"How could she feel nostalgia when he was right in front of her? How can you suffer from the absence of a person who is present? You can suffer nostalgia in the presence of the beloved if you glimpse a future where the beloved is no more."

It finally makes sense to me, and in the most peculiar way.