When someone says this just reply "so do i,(pause for a second) how unlikely that we meet"(show much sarcasim)"Maybe we meet here today for the same reason those (what ever you where using cards, coins,etc.)(did whatever the effect was)."magic"(STILL SARCASTIC).
People have the right to be stupid.But most hecklers abuse it.
So you say, "So do I. How unlikely we meet. Maybe we meet here today for the same reason those cards changed to aces."
Two things. This makes no sense. There is a wide range of sarcasm out there, and very, very mild sarcasm sometimes is funny, but done badly, it makes things worse.
Be careful about thinking about how stupid your specs are, especially if you recite sentences like this.
It is probably best to say something like, "That's wonderful, I am proud of you." If you don't think the person will shut up, then I might add, "Let's just keep it our little secret."
If you are doing a real show, you have to stay in character. If you are not sarcastic during your show, you should try not to be to a heckler.
If this is just dealing with other kids in your school cafeteria, then do what you want.