We are now at a point of unprecedented genetic, cultural, and environmental power as a species, and we are linked to nearly every other person on Earth. We are embodied individuals trapped within limited time, but we are also networked data streams, memories, and influencers, and part of a grander humanity. Our decisions today have far-reaching impacts that place a responsibility on us to become good ancestors, to take the long view and time travel forward to imagine the wellbeing of billions of people whose lives will be lived in the world we are currently making. Centuries ago, leaders of the native North American Iroquois people created "seven generation stewardship," instructing people to consider the impact of every decision on their children, seven generations into the future. In the precious few decades that Earth is ours, while we enjoy the gardens planted by our ancestors, we must not steal the shade from our descendants.