alt Hacker Newsif it helps...absolute pitch is _mostly_ a natural innate ability and cannot be trained.("Mostly" because recent studies have shown that you can train kids at an early age.) So you don't need to worry about not having absolute pitch, like you shouldnt worry about not having mensa level iq. What's more important though, is relative pitch, which most people can train for and is really valuable as a musician.
I was in some music classes early on (piano and guitar) and in band from middle school through the end of high school.
If I have perfect/absolute pitch (very doubtful), it's from having certain pitches absolutely burned into my brain. B-flat and F on brass instruments, C on piano, E on guitar, etc.
I can generally memorize and sing back the exact pitches of any song once I've heard it a few times. If I like the song enough, that pitch memory is forever. I will never sing it in the wrong key ever again and that's actually how I get around in music. I can always play back the original song in my head like a tape recording. I learned the names of some chords a long time ago from my favorite songs and now just know them by heart when I hear them (add9, sus4, minor 7th, etc).
Unfortunately, I cannot do this in reverse and name the notes or do any supernatural tricks like Rick Beato's kid. I would have to hum every individual note for a little while and run through the chromatic scale in my mind to tell you the name.
I think to a large extent, it can be trained. I didn't get started until I was like 8 years old and wasn't always the best student either. I hesitate to call this relative pitch because I don't need to hear an outside reference and I can very easily tell when an instrument is out of tune. I'm somewhere in between, and so are most band kids.