For atheists only: How do you generate meaning in your life?

I tell my religious friends that I'd like to believe in God, but I can't because it makes no sense to me at all. I've never had anything remotely resembling a religious, spiritual or supernatural experience. The evidence points overwhelmingly to God being a concept created by man. So from an evolutionary standpoint, is life simply survival and reproduction? Is there more? What do you live for? I'd like serious answers.