your pessimism against my optimism

there is an expression I hear quite a lot, "smile, it might never happen", I have had it said to me since I could remember. But even on these occasions where I may not be smiling, doesn't mean that I am feeling pessimistic, I believe that the more optimistic we are, the better our chances are of things going our way, maybe it is just coincidence or maybe just a simple smile can make such a difference, in not only situations, but within ourselves.