"I am too sad to tell you." B. J. Ader

Jack put it right. even though he is not a real person, only a character in a play.
Jack put it right:

"a certain world - that once existed - has died."

even though we read this as fiction, namely as a line of Wallace Shawn's play
"The Designated Mourner," it is an emotional expression covering grief and longing, sorrow.
certain worlds die everyday.