Rick Beato made several videos about perfect pitch, also featuring his kid who has PP and can identify entire chords. Apparently his opinion is that the key was

Rick Beato made several videos about perfect pitch, also featuring his kid who has PP and can identify entire chords. Apparently his opinion is that the key was listening to atonal music at an early age, like you say. Here's one of the more interesting videos: https://www.youtube.com/watch?v=816VLQNdPMM https://www.youtube.com/watch?v=816VLQNdPMM