{questions about the answerer are chatviolations, so I assume you mean in general As many as you have learned. I think the record is like 50, but that record is held by some monks who don't waste time on careers, relationships or having a family. I don't think it's feasible to maintain more than 10 or 12.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.