Ha Ha Ha

"These gentlemen are of such sensible and nimble lungs that they always use to laugh at nothing."
Meaning: Sensible means something more like healthy, or appropriate to the purpose here. Basically the insult mocks people for laughing pointlessly.

I totally disagree with this insult because why not laugh at whatever you want??? Even if it is nothing, there are tons of studies that show that laughing is soooo good for you. I read somewhere that even if you make yourself laugh, just the action of laughing releases a lot of stress, and makes you a healthier person. So ha, ha, ha.