When you're at that age where you don't know what the hell to do to impress people.
"No matter what you hear in there, no matter how cruelly I beg you, no matter how terribly I may scream, do not open this door or you will undo everything I have worked for. Do you understand? Do not open this door." - "Let me out!"
Quick Dam: While this only works with lower levels of water, it could buy you precious time in your house during an evacuation or when trying to fortify your place. Have several yards of it ready to go as soon as the emergency horns sound.