You don't need to believe in order to have a picture in your head. For most of us, the concept - some concept - of an afterlife has been part of our cultural matrix since birth. All of us have certainly been exposed to it in various forms and media. I think most North Americans have some visual image of a heaven, some notion of how it's organized, who is allowed in, and even of what to expect and how to behave.
In one version, i imagine walking across a bridge to a grassy meadow and all my dead pets come to greet me. I'd be really disappointed if it turned out that a dog's idea of heaven is never having to speak human again. (A heaven without dogs is unthinkable.)
What's your afterlife?