lost

I lost my metrocard. It is not the money; it only had $12 on it. But I hate when I lose things, because it makes me feel like I am losing my mind. I know I had it when I left Park Slope, otherwise I could not have taken the subway home. But this morning, when I looked for it so that I could go to the village to buy my sister a birthday present, it was nowhere to be found. And so I become half-crazed, looking everywhere to find it, when I should just let go.