The regenerative visions of dreaming across time and species. We're not the only beings that dream. What visions might sleep bring to a cell, an insect, a mollusk, an ape? Sidarta Ribeiro, the founder and first director of the Brain Institute of Federal University of Rio Grande do Norte in Brazi, takes us on a fascinating 1.8 billion years journey through the dreams of our ancestors. "Even knowing that our dreams are produced by brain reactivations during a specific phase of sleep, REM sleep, we cannot avoid the intimate impact of these experiences. If we can react with such awe and diligence to our own dreams, what can we presume about our ancestors: how did they dream? How much ancestry are we talking about?"