Why does repetition of religious ideas have no effect on child?

In the psychology cl I took last year, my teacher said that although parents/parental figures have very little influence on personality traits, they have a great deal of influence over political views, religion, etc. And when I was a little kid, my grandma would try and try and try to get me involved with religion - she was really . I was surrounded by Christianity. So why did this not have an effect? Now as an adult I am completely disinterested in religion.