> The perception of perfect pitch as this magical, unattainable thing always seemed odd to me.

Not sure why, it's taught and commonly considered to be an ability you're born with rather than something you can develop yourself later on.

> However, no adult has ever been documented to have acquired absolute listening ability, because all adults who have been formally tested after AP training have failed to demonstrate "an unqualified level of accuracy... comparable to that of AP possessors".

https://en.wikipedia.org/wiki/Absolute_pitch

The Wiki article also describes just prior to this cited section that there have been countless attempts at it over the centuries.

Doesn't exactly sound like a learnable skill to me.