Time, itself, is infinite. There was no "start" to time, nor was there a "start" to existence. Saying that, think of how new humans are to Earth, we are a 200,000 - 300,000 year old race living on a 4,500,000,000 year old planet. Seems long right? That's not it, Earth itself is one planet, revolving around one star, buried in one galaxy, among the hundreds of BILLIONS of galaxies out there. The universe is theoretically infinite, and again, so is time. So, with that big picture in mind, how are we not to think that at some point, there was no life on other planets, maybe even other homo sapien life. It is a little bit silly for humans to think that in the incomprehensibly large world that we live it, we are the only ones. Going back to the subject of Kepler 22b, also known as one of "Earth's Twins", why is it that we have billions and billions of life forms on Earth, but we are to say that it doesn't exist on Kepler? What if there are billions of planets out there with strikingly similar characteristics that we have not discovered, or never will discover?