BRAINLEST

What is the allusion in this passage? What two ideas are connected in this allusion?

Passage: I'm hoping the budding Picasso in my drawing class goes after that art school scholarship. I know in my gut that he would succeed, and the world needs more artists like him. The only thing holding him back is his own self-doubt. You know what they say: Aim for the moon, and even if you miss, you'll land among the stars. ​