The way the autistic "narrow interests" part of my #AuDHD manifest itself is not in the learning department. It's in the motivational department. I have broad lexical knowledge but a narrow ability to perform, especially if sustained effort is needed.
I sound like an encyclopaedia but I need help in everyday life, which I have only started receiving a little bit of in the past year or so. It's just really hard for me to take care of myself, even if the consequences are very bad.
It's a challenge to find a viable career when you're so picky. I worked as a software developer for over a decade, but with repeated burnouts. They kept giving me projects that were too boring to stay motivated. I tried out ADHD drugs to compensate, but they made me unstable, so I had to quit those, and the industry itself.
I can pretend to function like a normal human for a few months while I'm still excited by the novelty of the situation (such as starting school or landing a new job), but once everyday life settles in, things start to get difficult due to the motivational issues.
