Lately, I saw a video about the better ways of learning how to draw. The author says that after learning some basics, it is good to learn how to draw what you are trying to draw at the moment, because if you don't use what you learned you are likely to forget it before you may need it. I like this approach very much. Learning how to draw exactly what I want to draw also feels more motivating and satisfuying for me.

I also thought that the same principle probably applies to most areas, language learning icluded: if you don't use what you learned, you are most likely to forget it quite soon (though the exact speed depends on the person to my experience). I also heard that on the average Japanese language gets forgotten rather fast by both Russian and English native speakers due to the huge difference between them.