But to me it still seems as if you are saying "I was smarter-better-humbler-more spiritual than the other guy so God saved me."
It seems to me that it is you who is proud of being better than the guy who did not get saved. (That is not an accusation, just an observation regarding your charge that some who believe as I do are guilty of believing "I was chosen out of the world over someone else and be proud of it." Such is certainly not the case with me although I can't speak for any of the others.)
You say you chose to believe, but doesn't Jesus say "You did not choose me, I chose you?"
And doesn't the bible say that faith is a gift from God, not a choice of man?
So, back to the original question. Why did you believe and your neighbor did not? What about you was better than something about him?
Even deeper to the root of the matter is that faith is never a choice period.
You do not CHOOSE to believe in anything.
You are persuaded to believe it.
If you can choose to believe or choose NOT to believe- try choosing NOT to believe that you exist.
You can't.
You never in your life made a CHOICE to believe that you exist.
Choice has nothing to do with faith.