So Ive heard that when we sleep for a good 8 hours we dream quite a few times? But we only remember very little of them if any, is this true? How is it known that multiple dreams occur if most of them can never be remembered? This seems like a statement that cannot be proven? Its like saying you 3 cups of coffee everyday when no ones looking you just don't remember doing it? If no one else can see and you don't remember how has this been discovered?