Please stop using Albert Einstein as an example of an expert learner.....

..if you are just doing so on the basis of him being, well, Albert Einstein. (He was very smart = he was an expert learner (even through he dropped out of school/AND he dropped out of school)).

Hands down, the man was incredibly intelligent. He was a high school drop out, and as some have pointed out, book learning (as called here in some posts) did not suit him. People drop out of high school for a whole number of reasons. Some have to do with learning styles, some have to do with other things. Some people succeed to the nth degree even though they drop out, others don't. Others do unforgivable things with their lives afterwards; Hitler was a high school drop out, too; most don't. The point to be made is that school (or 'book learning') is clearly recognised as only a small fraction of learning or a specific source of learning. Furthermore, it doesn't mean the pupils are aware of their own learning activity. Learning how to learn in school will primarily help you achieve good results at learning in school. Anybody in a school system also knows that good grades/results doesn't actually mean that you know anything. Most know some things, but even in A students, the gaps in their knowledge once put to a rigorous test is clear.

Learning how you learn, however, and being able to use and challenge that, is a whole different kettle of fish all together. The question is rather HOW Einstein became and was an expert learner (or a 'good' learner as the question asks). Thus: Einstein had a different, and varied approach to learning, which also suited his ways of thinking and structuring his thoughts incredibly well. This match - although it took him his time - was a productive match for him and he succeeded in amazing things because of it. He was very smart = he managed to approach his learning on a meta level (I am not going to find all of the quotes and sources on this) = he developed into an expert learner, which he managed to apply to his own work.

Just saying he was a genius is a far too superficial approach to the more interesting parts of the question.