"A prudent man conceals knowledge, but the heart of fools proclaims folly"
This is the Hebrew word orma, which means guile, prudence, shrewdness. The idea seems to carry with it the idea of strategy to accomplish a goal. In other words, one needs to know what to share and when to share it so that a righteous goal can be accomplished.
This is the Hebrew word kasa, which means to cover, to conceal, to hide. There are many times that the knowledge and even the strategy you are following needs to be hidden in order to accomplish your goals. Solomon is stating that there are times for secrecy of purpose and goal in order to bring about a righteous end.
This is the Hebrew word data, which means knowledge and skill. Not saying all that you know or all that you can do is strategic at various points in your life.
This is the Hebrew word leb, which is the standard word for the inner part of man or the soul. Notice that the soul of the fool is what proclaims what the person is about – the whole idea of what you think about proclaiming whether you are a fool or not. If you are consumed in your mind with yourself, with what you want, and with your pleasure, then you are a fool.
This is the Hebrew word kesil, which is a standard Solomonic designation for a selfish, rebellious, impulsive person: the fool.
This is the Hebrew word qara, which means to call out, to call, to recite. The idea is of proclamation or announcement. When you ask fools what they are thinking about, the answer is themselves. They want themselves to win even though others – even lots of others – lose. They do not think of ways to bless others; they think of ways to bless themselves.
This is the Hebrew word ewili, which means foolish, folly. The whole of folly is that which is selfish. It is what I really want to do with little thought to consequences, to impact, to others. What the fool is thinking about just screams out selfishness.
One of the things that you must learn to do is to focus on benefiting those around you as you are looking to benefit yourself. Your choices and actions must encompass both or they are not an option. You must also develop an ability to be strategic about the accomplishment of your wise goals. You must also realize that the world does not revolve around you. You have a part to play in God's plan, but you are not the center of His plan for the kingdom.