Time. It's something a drummer obsesses over almost more than anything.
How do you go deeper with your concept of time? How do you begin to understand the finer details of subdivisions?
Don't just watch the video. Try this exercise out for yourself.
The Moving Click exercise will quickly reveal any weakness in your understanding of accent & pulse permutations. The exercise will increase your ability to detect time fluctuations almost immediately and fix them. (It will also help to develop patience and concentration.)