Not long ago, I was diagnosed with a learning deficit, though it was never given a name and wasn't really talked about at any depth. For reasons which I won't discuss, I had to undergo a psychological evaluation and was told of the deficit months later. A lot of people in my life have dismissed that as the psychologist doesn't know what he's talking about, but for me the finding made sense, and it applies to anything from remembering where I put something or when an appointment is, to trying to learn things in school.
Basically I only remember things that I can systemize, and or that I can somehow set a priority on to code into something that'll stick. I cannot focus on two things at once to save my life. Dealing with raw language or random information is my biggest deficit. If you give me a sequence of as few as four numbers and ask me 10 seconds later to tell you what it was, I might not remember one digit, or if I do remember a digit or two, I'll forget the order they were supposed to be in, especially if I'm even a little distracted. If I'm not distracted, if I don't have to do anything else, then that 4-digit sequence isn't as hard to get down. But if I'm even a little distracted then I completely forget it. How long it takes me for something to get from shortterm to longterm memory is something I don't yet know.
With 16 items to remember during the test at the psychological evaluation, it didn't go so well. I only remembered maybe 3 of the 16 things, compared to the supposedly normal 7/16 on first run. I think the reason I had such trouble was that I was on information overload; I didn't have time to concentrate on remembering the first word or two before I was hit with more. Which is just as well, because trying my hardest to remember all 16 would've exhausted me to death anyway. With repetition I did improve, but not as fast as they thought I should. I could barely remember half the items on my fourth run (IIRC I only got 6). And I think they would've expected about twice that amount normally.
As it turns out, this type of memory lends itself well to my musical aptitudes. Because I'm blind, I have to memorize pieces of music I perform, or ideas I have if I"m composing. I've gotten really good at memorizing pieces, but it was while in college that I learned an important lesson.
I have perfect pitch and can hear notes very easily, and so there is a common stereotype that such people can just learn things instantly the first time they hear it. This is sadly not the case. I can never remember the notes I hear in a piece of music. Trying to write them down and recall them isn't good enough, even trying to visualize playing them, the sound of each note, or my hand positions at the keyboard aren't good enough. I have sound/texture synesthesia, which means that certain notes and musical keys produce different textures and sensations that I can trace, and some people with synesthesia have said it helps them to remember, but for me, the associations are subtle and don't help me much. At best, my synesthesia can help me remember what key something is in or what instrument should be used, but not the notes. I tried to use all of these strategies to get better at retaining music, before I came to the realization that I had to sit down and play what I heard as I heard it, and actively stimulate myself.
Fortunately, playing what I hear without thinking is something I'm pretty good at. I'd take a ppiece in chunks of perhaps 3-6 notes at a time and get each chunk down in my memory simply by playing it a few times, without analyzing details. I can also, for the purposes of learning, encode chunks in a sort of simpler form in realtime, for instance if something repeats or follows a pattern that's easy to pick up on, or if there are multiple notes at once which I can chunk into a single block. I start to build a roadmap of sorts which I can decode as needed while I'm playing until I get to a point where I don't need it. Surprisingly my synesthesia can help me out because I'm actively engaging it with aural and tactile stimulation. I can sense a dip here, a rise there, a circular shape represents something that repeats, a spiraling shape represents a pattern of some sort. A flat wide landscape indicates a lot of white keys, a thin tall landscape indicates black keys. These shapes no doubt are triggered by the motions my hands have to make at the keyboard, but sometimes tehy get really profound and I can't explain them that way, especially when I am composing or doing sound design. In any case, I can see these shapes in my mind's eye in a sense. This allows me to learn large amounts of material in a short time, so long as I can hear and physically play the notes. Now, if somebody asks me to tell them what notes I'm playing, I have to decode all that tactile-sound roadmap I've constructed into language... This is a slow process because as I said I do not have a memory for language. I have to remember a few notes, speak their names, purge them from my memory, and repeat on the next group of notes. I'm not really fond of the process.
I'm able to downscale my way of learning to meet different demands. The system I was talking about is what I used to learn classical things and get things note-for-note, but I also play other genres like jazz, fusion and others. Just a few weeks ago our band had to learn about a dozen new songs, a few of which were actually difficult comparatively. Learning non-classical music is easier in a sense though because a lot of what we're playing is improvised, so I didn't need to learn exact notes. This being the case, I don't necessarily need a keyboard to learn chords, I can actually learn while listening, but it's still difficult to retain. Sitting at a keyboard made it so much easier and it's the only way I can learn melodies or specific lines I have to play. I basically learned the chords for all of our new stuff over that two week period. I was able to sort of filter out details that wouldn't be necessary to learn, like the exact notes I heard, but was still able to absorb the chord as a whole. The exact notes I play were left to my disgression while performing, and so I consciously didn't learn anything concrete, and my ability to improvize is probably why I was able to do this.
So through all of this I've learned I cannot rely on my informational memory; I do far, far better if I can get to a place where I don't need it.. I don't think this is something I desperately needed to know to live my life, since even the psychologist who evaluated me agreed that I compensate so well that there's nothing to be said about it really. But it fascinates me, since it hints at why I struggled so much in many subjects in school. The more complex the information became, and the less I could connect with it, the more magnified my focus difficulties were. Sadly, I never picked up on this pattern of memory as a child, and it seems nobody else did either or knew how to help me. I had to discover this on my own and I am a lot happier now that I have. I'm so glad to know that it seems aspies process and remember differently for the most part, and that I am often not alone in my retention difficulties.