Six is barely 'old'. Old in a cat is around 19 or 22 now. He needs the rabies to comply with state law, there's a 1 year vaccine and a 3 year vaccine, find out which one your vet uses.
If a mouse got into the house and he ate it, he could have worms if the mouse had the parasites. It won't hurt to get a fecal exam done on him. We didn't let ours go outside either but unknown to us a bird flew into the basement and one of ours got it.
A week later we see worms in the poop in the litter box and all four cats needed to get treated. More.
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.