This is an interesting topic, but simply put one learns better when enthusiasm and joy is there... small children learn by playing and that is the natural way of learning, so i would say if you can play with your topic you can learn it and the knowledge will stick because there is an emotional attachment to it. Research on this topic has been done by Dr. Gerald Hüther professor and neurobiologist. Also you can look up how unschooled kids learn (since there is no school they play all day long) and even succeed very easily when they decide to pursue college degrees... that brings lot of insight on how we as humans learn about the world around us (and the topics we like too)