Prayer

Warning: *venting.

Why is it that sometimes the smallest prayer doesn't get answered? I know that prayer is a powerful thing. I am a witness to that in my own life and I see it answered in the lives of people I love and care about.
But why is it that sometimes when I say the smallest prayer it just doesn't seem to get answered. Then I get to the point of wondering why I bother.
I hope you know what I mean. I am not looking to have sympathy or to have biblical verses thrown at me. I just get so frustrated and confussed. I know within a hour or two I will want to delete this post but for right now it is a venue for me to let it out.
I know that He doesn't answer EVERY prayer and He has a reason for not doing so. But sometimes I just wonder. Like this morning. I hope He doesn't get mad at me. I have been told that He is not that kind of Father. But being human I fear that I will no longer be blessed just because I am complaining about one small thing. But He knows me better then myself so I guess He knew my questions and doubt were coming.