Light is the first and the main reason that we know the rest of the universe is there. Neutrinos are the second, and gravitational waves are only the third. It's easy to forget how tenuous our connection to the rest of existence is.
What an interesting thought. If the rules for light were different - if light faded after a few AUs of travel, we wouldn't have known about the existence of the rest of the universe. Our preoccupation with the stars - the stories we told - would be different.