Yes hubbers aren't allowed to click on other hubbers ads as well because they are HP ads. You can get traffic from HP itself and earn from the HP earnings program.
I fully agreed with catrus. The best way to get revenue from adsense is not think about it much. Concentrate on your traffc instead.
The more visitors you get more chancesd will be there that they will click on ads.
If you want to earn with adsense, your goal should be to ultimately drive organic traffic.
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.