This term means that it would make you very clueless and ignorant of the subject you are asking, if you ask a few questions, and this in turn would make you more knowledgeable, and a greater insight into it, making you more smarter. But, if you don't ask any questions, there would be lots of buggering doubts in your brain that you can't find the answer to it, and you will never inquire about it, never try your best to find the answer, and you will be blind forever from the world outside, making you more like a fool to others.
What Does The Quote He Who Asks A Question Is A Fool For Five Minutes; He Who Does Not Ask A Question Remains A Fool Forever Mean?
I would take it to mean that it is better to ask a question which could show your ignorance on a subject but leave you smarter and more knowledgeable for gaining the answer. Rather than never inquiring and trying to learn more, therefor remaining ignorant forever