The complexity of a learning problem is often determined by the size and structure of the hypothesis space.

释义：人如果没有喜事，精神就会萎靡不振；当运气不好、处境艰难时，往往会感到更加落寞和失落。

最好的肥料是农民的影子，没有什么能取代在田间的存在和关注。

The best way to learn a new programming language is by writing programs in it.

在弦理论的早期，我们就像是在绘制未知大陆的地图的探险家。