Severe autists have a built in reset button. If we make too many mistakes while performing a skill, we forget everything and have to learn it anew. This turns out to be a safety feature. Having a photographic memory means that we can learn complicated skills quickly. However, it also means that we can accidentally learn a skill the wrong way.
To learn complicated skills, it turns out to be easier for severely autists to learn the entire skill at once, than to break it up into pieces. For example. When neurotypicals learn to read notes they start with the whole notes and then add the half notes. For severe autists it turns out to be easier to learn whole and half notes at once.
Mental health organizations have found in their research that severe autists cannot learn to play one simple song. This is true. Learning to play one simple song is so boring that our brain falls asleep. However, learning 20 simple songs at once isn’t a problem.