MongoDB update does not work properly?

Your code should be OK. As you developed your code you probably tested it a couple of times and updated the document with bad modifier documents. Now there's garbage in it.

Just test it with a clean document.

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.