The main reason is the good curriculum design. I have listened to other classes, such as what is what, what is the fire and what generation,

A simple tool walked around for half an hour, which made me want to sleep.

I don't feel sleepy when I study Trogg's course. Every sentence is very useful. My brain has been thinking about the course.

I don't have time to sleep with Ben.

There is also the design of homework, which feels good and in place. It seems that you can design and make Internet elements by yourself when you just learn the seventh lesson, which is not the kind of rote learning step.