For example a text I worked through with exercises to determine the cache performance of code snippets, ie: the total number of reads, the miss rate, ect. When I first did that chapter I'd just work through the exercises and move on. Then I'd forget everything a month later. The second time I explained the answer to myself like I was giving a lecture, after working through each exercise for example explaining spatial/temporal locality, stride-1 reference patterns that will be prefetched by the cpu, ect. That was about 2 years ago and I still remember that chapter. So slower at first, but you remember all the concepts which means you don't have to go back and re-do the material again which for me is 'faster learning'.
All three above will get you asking questions and seeing the thing from angles you wouldn’t have thought about otherwise. It’ll also connect your knowledge to existing knowledge which is ultimately what will make it stick around.
I spend a LOT of time learning new things . I’m perpetually perplexed and live in a constant state of confusion about a large part of my current thoughts, and the way described above is how I perpetually integrate the new stuff effectively.