Carl Sagan’s passion for exploring worlds beyond our own began as a child growing up in Brooklyn, when a the age of five he began frequenting the New York Public Library to browse books that could give him a better understanding of the stars. He later reflected on the what he discovered: “There was a magnificence to it, a grandeur, a scale which has never left me. Never ever left me.”
Sagan pursued hispassion into adulthood writing later: "All my life, I've wondered about life beyond the earth. On those countless other planets that we think circle other suns, is there also life? Might the beings of other worlds resemble us, or would they be astonishingly different? What would they be made of? In the vast Milky Way galaxy, how common is what we call life? The nature of life on earth and the quest for life elsewhere are the two sides of the same question: the search for who we are."
The Daily Galaxy via Library of Congress