Phineas has been liking coffee-flavored things (mostly candy). Ezra wants to know why kids aren’t allowed to drink tons of coffee.

Me: “Well, coffee contains caffine which is a drug, like medicine. And we have to be careful because these things are usually designed for adult-sized bodies and putting the wrong ammount in a kid-sized body could be dangerous.”
Ezra: “Because we would die?”
Me: “No, probably not. But you could get really bad stomach cramps. That would hurt. Also, growing bodies react differently to some drugs and if you drank coffee a lot that might be bad. But a little bit is fine.”
Ezra: “Yeah. Because Phineas likes coffee.”
Phineas: “Yeah! Because I am a coffee-man who does not drink very much coffee!”