Certain secrets can’t be left behind.

[suprunp]

Tengo and Kumi are talking about 'a hole that opens up in the world after a person dies.' Kumi says that this hole can't be left open, or somebody might fall in.

“But in some cases the dead person has secrets,” Tengo said. “And when the hole’s filled in, those secrets are never known.”
“I think that’s necessary too.”
“How come?”
“Certain secrets can’t be left behind.”
“Why not?”
(H. Murakami; 1Q84)

I don't quite understand this. When a person dies and 'the hole's filled in', so to say, the secrets that the deceased had are still there, lingering in the air, unresolved, as it were.
So what could she mean by saying that 'certain secrets can't remain after a person dies'?

P.S. Ah, I seem to have got this. If the secrets were known only to the deceased they are never known to those who are still alive and, therefore, they can't remain unresolved simply because no one else knows about them.

Thanks.

 

[BobSmith]

If only there was an answer to the “Why not?” Then we'd know.

 

[suprunp]

If only there was an answer to the “Why not?” Then we'd know.

“There’s something about those secrets that only the deceased person can rightly understand. Something that can’t be explained, no matter how hard you try. They’re what the dead person has to take with him to his grave. Like a valuable piece of luggage.”

 

[susiedq]

Yes - certain secrets can't be "left behind" in case they are apt to be revealed.

(Like the family fortune was made through illegal means)

They are "taken to the grave."