By topic/idea, it can range from philosophies, areas of study, struggles, etc that you wish more leftists would give more attention to. In your reponse, pointing to a subraddle, wiki, or your favourite resource on the topic would be welcome.

In my experience, it has to be the huge number of leftists who don't realize the importance of establishing ourselves on anti-corporate, free platforms. But clearly we are all here since we agree with that!