This quote is often attributed to Galileo but is actually the last two lines from Sarah Williams‘ poem “The Old Astronomer.” You can read the whole thing here if you want.
To me, the lines mean we don’t need to be afraid of the dark times in life.
The following is from Walking on Water by Madeleine L’Engle:
“Milton could have retreated into passive blindness and self-pity instead of trying the patience of his three dutiful daughters and any visiting friend by insisting that they write down what he dictated. Beethoven could have remained in the gloom of silence instead of forging the glorious sounds which he could never hear except in his artist’s imagination. Sometimes the very impetus of overcoming obstacles results in a surge of creativity.”
If Milton remained afraid of of his blindness and never faced it, we wouldn’t have Paradise Lost. If Beethoven cowered in response to his deafness, we wouldn’t have Symphony No. 9 in D minor. Instead, they embraced the stars so fierce night no longer had a hold on them.