Subconscious

According to Qatal, "many things" were buried deep in the subconscious of every Time Lord, including their "entire history", and forgotten forms of ancestral language, like the ancient Gallifreyan word for stardust. (AUDIO: Hostiles)

Behind the scenes

 * Although not mentioned in the episode,, as played by Sacha Dhawan, said very similar about the mysterious Timeless Child in series 12 episode Spyfall: Part Two.