chance is definitely a credible answer, especially going off what we understand right now...
but none of this is normal man... we're collections of atoms exhibiting CONSCIOUSNESS, RATIONAL THOUGHT. I like thinking about how crazy that is sometimes.
"In some strange way an electron or a photon [or any other elementary particle] seems to 'know' about changes in the environment and appears to respond accordingly," says physicist Danah Zohar. A group at the Weizmann Institute in Israel has done a variation of the famous "double-slit" experiment. They used electrons, instead of photons, and observed how the resultant interference pattern (which indicates wave-like properties of the particle) dissipated the longer you watched the electrons go through the slits. As a wave the electron passes through both slits simultaneously but if, according to E Buks, it "senses" that it is being watched, the electron (as a particle) goes through only one path, diminishing the interference pattern. Elementary particles (such as photons and electrons) appear to possess a certain degree of "intelligence" and awareness of the environment. Renowned plasma and particle physicist, David Bohm, says "In some sense a rudimentary mind-like quality is present even at the level of particle physics. As we go to subtler levels this mind-like quality becomes stronger and more developed."
http://www.dapla.org/conscious_particles.htm
"An approach to the mind-body problem based on physical laws has been advocated by several thinkers. Quantum Theory has been particularly intriguing for scientists eager to provide a physical explanation of consciousness. Loosely speaking, the point is that consciousness is unlikely to arise from classical properties of matter (the more we understand the structure and the fabric of the brain, the less we understand how consciousness can occur at all), which are well known and well testable. But Quantum Theory allows for a new concept of matter altogether, which may well leave cracks for consciousness, for something that is not purely material or purely extra-material."
"No wonder most neurobiologists reach the conclusion that Physics cannot explain consciousness, since they are using a Physics that 1. was designed to study matter and leave out consciousness and that 2. does not work in the microworld. Not surprisingly, it has been claimed that all current neurobiological models are computationally equivalent to a Turing machine."
http://www.scaruffi.com/science/qc.html
let it simmer