A speaker uses a vivid image: your mother is on a cloud, and you must build a tower to reach her. Will you spend the night asking why, or wake up and start building? The point is simple: stop wondering and start acting.
Who's the person that you care about the most in this world? My mum. So if someone came and took your mum and put her on a cloud in the sky, and the only way that you could see her again is if you built a tower high enough to be able to bring her back down or to be with her again, would you wake up tomorrow and wonder why you? Or would you get building?
