Our being restricts the environments we could potentially find ourselves in. We could not exist in a solar system with two suns, and thus find ourselves in a system with a single sun. This type of deduction is called 'weak anthropic principle'.
The Grand Design
The laws of nature seem mysteriously crafted to allow for complex life. Scientific explanations involve the existence of multiple universes with different sets of laws. Thus, a universe with our set of laws is no more special than the unique configuration of our solar system or the very planet we live on.