Science cannot even in principle explain why we have conscious experience. Further, a substantial portion of educated people seem to be fundamentally incapable of appreciating this. These people will tell you about the neurobiological correlates of consciousness, they will conjecture about the functions of consciousness, or they will say it isn't even interesting. Descartes said the most undoubtable fact is the existence of experience, but at the same time, it is (along with the question of why there is something rather than nothing) the most ultimately inaccessible problem of science.