What does historian wear many hats mean?

I think it means that historian or a lot of hats because that's what they do in their life and this is America so you never know what will happen in history in the future something that's what they mean by how many hats because it doesn't matter how many Freedom you have it matters how many like because everyone they have different lifestyles in different countries and states and Americans so never be ashamed of what you do in life or in the future because what you do now is what is going to happen in the future to other people what you are like a historian or an American