One thing I was taught from an early age by a very intelligent self educated man with a 3rd grade education (my grandfather): "Your education is the only thing you ever really own. It's yours. What you put in your head is something no one can take away from you." His greatest gift, it taught me the power of knowledge. Another thing he taught me: "What decides the outcome of a battle is the difference between how good you are and how good your enemy THINKS you are."
What I taught both my boys:
You don't win wars by just mindlessly shooting and stabbing each other. You win wars by attacking and destroying an enemy's supply lines and communications.
The main tool you use to do that is intel. As an adult you get your intel from reading. You read to get an education, you go to school to get a degree. If someone tells you not to read something, they are trying to deprive you of intel. So, if someone tells you that you can't read something, for whatever reason, you read it. As soon as you can, before they take it away. Then store it in your head for the day you may need it. No one EVER, ANYWHERE, has learned themselves to death. And no one has ever wished they were dumber. And NEVER let anyone know your real capabilities. Don't show off or try to impress. My oldest son is a martial artist, boxer, pistol shooter and shotgunner, and denies any knowledge of any of it.
Jeff Cooper said it very succinctly: "You don't fight with a gun, you fight with your mind. The gun is just the cutting edge." My source for the quote is that I watched him say it.