A warrior doesn't have to be the smartest person ever, but a warrior must be dedicated to always learning. You don't have to be in school to learn. Anyone can study anything on their own. So even if you've graduated high school or you're not in college, you still can learn.
Additionally, as I mentioned in the blog "You Don't Know It All," people who think they know it all and refuse to learn new things are only hurting themselves. If you refuse to accept that you don't know everything, you will never be a warrior. An intelligent person can accept their mistakes and learn from them.
A warrior is always studying, always learning, and always trying to improve. To be a warrior you must always keep an open mind and make an effort to learn more.