Original and Fake

He was from the start, one who would disappear after being summoned.
No matter how many hundreds, thousands of times he would repeat that, it wouldn't remain in his memory.
The only thing that would remain is the knowledge that it happened; what is recorded as knowledge on his base.
How Heroic Spirits know of other Heroic Spirits is through the growth of knowledge from the "accumulation of summonings."

It's like receiving a book.
Each time he's summoned, the book of that history would be sent to his house.
While he ought to have already left, he's still in the house as an entity that can only look at the sent book.
The problem is exactly when that book was sent. Not even he knows.

Notions like the past or the future don't mean anything.
His room had all the "books" from the start.
Unable to tell time through any other method except by reading the records of his "clean-up" jobs that he would fulfill one day.

To him, an eternity is no different from an instant.
An eternity is an instant, an instant is an eternity.
And because of that, he couldn't even tell just how unlikely a chance this miracle he had grabbed on to was.

He may have been summoned immediately after he had gained that hope or he may have been summoned after thousands and thousands of times of repetitions since he latched on to it.
.....All he has is knowledge that is without any kind of temporal order.
The future, past, and present is something that can't really be defined for the Heroic Spirits.