"The problem (one of the many problems) with this idea is that not only can one not know that a thing exists when it is not being perceived, but that other people may not exist as well. This must, of necessity, lead to solipsism, the belief that one is the only conscious entity in the universe. Or, for that matter, than beyond one's own consciousness, the universe itself does not exist".

This is all under the assumption that "WE" are the only beings on the planet that are capable of awareness, comprehension and a beleif that something may happen in the future!