“I'm going forward. I know — because I went.”
Source: The Time Axis (1949), Ch. 25 : Return Voyage
Context: I'm going forward. I know — because I went. It was a wonderful world they had. I want to see more of it. I want to wake up in a time when the race of man is spreading through the galaxy, leaping across the gulfs between the stars, opening the gates to all the worlds. I want to and I will.