The Buddha says: Every meeting has a parting.
Those moments when you meet someone and literally, especially on medium, the world falls away. For me some have only lasted from say 9 p.m. to 7 a.m., with friendship ever after. Others have gone on, regardless as to who was involved with.
Somethings can never be, but oh the glory of having been there for awhile. For all that is lost, as the lyric says, the music's over, but the melody lingers on.
The loss is nothing compared to the unity that was and to some extent still is, says me, with no knowledge, other than my own experience. Having had a similar loss, but by death, can only say, would rather the pain, than to go through life, never knowing them.