When Adrian heard his past self speak those words, he was overcome by a strange feeling. This was a very significant memory for him, and he could still recall it vividly, as though it had all happened only yesterday.
'Looks like my initial guess was wrong.'
After witnessing the first memory related to his grandmother and listening to the tale of the legion commander, he had guessed that Immutable was showing him his past trauma.
Although that memory with his grandmother had been very significant to him, he didn't really think it was the source of any mental trauma. Still, he assumed that it actually was, and he had just not realised it or was subconsciously denying it.
But witnessing this second 'teleportation' made him certain that his previous assumption was incorrect and that what Immutable was showing him was not related to trauma or something negative.
'From the start, Immutable had been strange.'
