Surprised not to have seen it elsewhere, but I remember telling my mom that we began studying astronomy in grade school (5th or 6th?) and she gave me Cosmos by Carl Sagan. I didn't know there was a TV series for it at the time, where reading it truly blew my mind that there were other galaxies and stellar objects beyond the Milky Way, and how happenstance humanity's origin story began. It also provided a great foundation for understanding what future missions would explore: finding habitibility zones outside of the earth, probes zooming to the edges of our galaxy, radio telescopes designed to listen for signals from far away, and space telescopes expanding our map of the cosmos just to name a few.