Could you tell me how to use this expression “that’s that real stuff”?
Good question. "Real stuff" is an informal phrase used to say that something or something is authentic, credible or genuine. Here it is used to show that he has the authentic or "real" abilities of a paperboy. So, "that's that real stuff" here is basically saying that his action is proof of his greatness a paperboy. You can use the expression whenever you want to refer to the authenticity of something. Ex: A. Which drink is the best? B. The purple one. A. Really? B. Yes, that's that real stuff. Ex: This designer is the real stuff. Everything fits beautifully.