Last May, when I learned I had a malevolent disease, one frightening thought kept floating back into my head: "gosh, this thing may kill me." But after a while, my fearful reaction surprised me. Of course, we all die. So what exactly made this news different? It was my assumption I would live long - to a 120 years specifically. One fact, one assumption and one aspiration had created more than an assumption, it had morphed into an unstated, firmly held belief.