Ask HN: How do you remember what you learn at work?

It seems I have a very weak memory:

1. I can't recall 90% of the details of projects I completed even if they were as recent as 2 weeks ago. When people later come ask me about the project, I blank out.

2. When I learn about some other colleague's system, while I can pick it up and learn about it very quickly, I forget all about it after a few days. This led me to never really understand the underlying system of the team and always feeling like I'm missing something.

I'm experiment with building personal knowledge bases (using Notion) and using spaced-repetition for the key systems. Any other suggestions? Could not being motivated about the team also be a factor in this?