略知皮毛者总爱反复谈论那点皮毛。

People who knows a little always like to talk the little.

对于这件事，我也只是略知皮毛。

To know a little superficial knowledge about something.

略知皮毛的人的一个特点是，他们总是要装出一副大有学问的样子。

It is characteristic of people who have only a little knowledge to try to pretend that they have much knowledge.