If the whole universe has no meaning, we should never have found out that it has no meaning: just as, if there were no light in the universe and therefore no creatures with eyes, we should never know it was dark. Dark would be without meaning.
C. S. Lewis
In simple terms (just in case someone didn’t understand)
If life and the world have no meaning then we would have never realized that. Just like a world full of eyeless creatures would never realize it is always dark.