What does it mean when you add a tag, and that tag shows up in bold, whereas the other tags are?

That means the tag you tried to add was already in the list of tags. The bold text is simply to alert you that the tag is there already. If nothing happened when you tried to add a tag, you would be confused and you could think the software was not working.It is simply a visual hint to help you, it means nothing for that tag or the other tags.

To me it doesn't matter. From the search engine perspective, the font-weight has no value at all.

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.