I think introductions are probably the toughest parts of an essay to write. I don’t think they are as important as the body paragraphs though, so if you have to cut corners to save time, it is probably best to do more of a template-based introduction and save the time. But if you can write a creative introduction, that is best. It is good to start off with some general statements or ideas about the topic and gradually focus narrower and narrower, ending at a specific thesis. If you can tie in a quote or saying, or something from popular culture, I think that is a good way to draw in the reader’s attention. For instance, the first thing that came into my mind when reading this prompt is the part of nearly every kung-fu movie where the wise master says, “Now the student has become the teacher.” So I would probably introduce that and state that like the kung-fu master, you cannot really tell if a student has deep understanding and mastery of a topic unless the student is able to explain that topic to others so that they can understand it too. After all, isn’t that what education is really fundamentally about, passing on knowledge to others?
I guess being an “old man”, well at least almost 50 
gives me a little advantage in the life experiences department. I don’t really have any quick 'n easy ideas to improve your background knowledge - I think that is actually something the GRE is trying to test you on. I suppose students who are well-rounded and have read about a large variety of topics will have an advantage. Unfortunately, it also comes down to luck somewhat, in that you might get a topic you are very interested in, or you might get one you have never really thought about at all. Sorry I can’t be more help - maybe others on the forum have some ideas.