The Fear of the Lord is the beginning of knowledge, but fools despise wisdom and discipline.If we were to understand the Fear of the Lord as something that is played out in life. Not as simply an emotional response or a passing thought, but as the emotions and thoughts manifesting themselves in action.
(Similar to coming across a bear in a forest. I wouldn't simply pull up some knowledge about bears in my mind, and I wouldn't just let that knowledge cause my heart to beat faster, I would most likely run, if the bear wasn't too close, and I thought I could make it someplace safe. Or what about seeing the great pyramids for the first time. I wouldn't be satisfied with a simple mental snapshot of the pyramids and I wouldn't stop at being awed, I would go up and touch it and see if I could go inside and explore or climb it.)
True fear and reverence manifests itself in action. The same is true with the fear of the Lord. If you have the true fear of the Lord, then you will put it into action by doing what He says.
If you are not doing what he says, to follow the verse, then you haven't even begun to know anything.