I recently asked this question which was about What topics do I have the prerequisites for? and the question was closed because it was “Not suitable for this site”. The reason was “Seeking personal advice Questions about choosing a course, academic program, career path, etc. are off-topic. Such questions should be directed to those employed by the institution in question, or other qualified individuals who know your specific circumstances.”
As I stated in the question, I am not a college student, so I am not at any institution and I am not choosing a course, academic program, or career path. I am learning math because I just like it, and since I am not a college student, I can’t ask “other qualified individuals who know your specific circumstances”. The only help that I can get is online here.
I am sure that questions of this type have wide applicability for this site because there are many self-learners who don’t know what to learn next because they don’t have any guidance on what they can learn next.