Since you brought it up, please answer this: imagine you run out for supplies. When you return, you see a phone message. You play it: "Hey, it's me. Came up with a new riff... what do you think?" followed by 10s of guitar. You forget to hit save, so didn't avoid an auto-delete, and didn't take notes. After the echoic memory time runs out, what will you remember and what will you forget?
We tend to remember things we can contextualize- things like stories, patterns, melodies, ideas. We tend to forget information that we can't connect to a context- strings of random numbers, random pitches or letters, and sound fidelity that isn't connected to the context of a direct comparison.
For instance, if I do a controlled listening test between two similar sounds, I might remember that I thought one of them sounded better. But if you presented me with one of those sounds without the context of the other one, I wouldn't be able to tell which one it was.
The length of auditory memory for sound depends on how different it is. We can easily remember what muffled or harsh sounds like in general, but it's impossible for us to discern two reasonably similar quality sounds when presented to us with a more than a few seconds between them.
You can test your own auditory memory pretty simply. Take a music track and alter the response 2 or 3 dB in some part of the range. Listen to it directly next to an unaltered file and prove that you can discern the alteration. Then start inserting 1 second, 2 seconds, 3 seconds between the samples and find out where your accuracy starts to fall off. It's quite difficult, not just because of auditory memory, but because our ears tend to adjust to slight deviations over time. The longer the sample, the less likely you would be able to discern which one it was.
The sorts of potential differences we are talking about with DACs or amps are very small. The only way for us to grade them accurately is a direct A/B comparison. You can't trust your memory for stuff like this.
I can't really guess what he may or may not remember. He might remember all that with very little bias, or it may have been meaningless gibberish even back then. I'm unable to tell.
He's remembering his emotional reaction to listening to music, not precise memory of the fidelity of it. He is just attributing the emotions produced by the music to the fidelity. That likely isn't what's causing his emotional reaction.