If you don't believe in life on other planets...

...then that includes our planet, too. In my self-philosophy post, I talked about how it mathematically makes sense that there exists life on other planets, due to the infinite nature of the universe. Well, if you believe that Earth is the only place in the universe where life exists, then that's one out of an infinite number of planets, and one divided by infinity is zero in the math world. So, if you believe that life doesn't exist on other planets, make sure you include Earth on that list. Although it might be easier to reassess your beliefs.