Look at this example for a moment. (Look at it! 🙂 ) Do you realize that, as it is currently written, the second sentence says you are opened, rather than the box? Also, there’s a serious noun-verb error in the last sentence (things are, not things is — the verb doesn’t belong with life or point).
One day, you receive a large box in the mail. When it is opened, you realize all the things you’ve lost in your entire life up to this point are in this box.