As an atheist, what do you believe without question?

and with as much conviction as the religious-minded folks do of their gods? I believe that my wife loves me as much as she says she does, and that no matter how many times I am a complete douchebag, or behave in a selfish or stupid manner, she will continue to love me beyond measure. I will always do my best to please her and to make her happy, and that gives me great comfort, no matter what may come in the future. What about you?