Florian is in the habit of choosing his words advisedly. When he was younger than Justin is now, he already knew how perilous it could be to say the wrong thing.
Justin knows it too, but the knowledge only makes him the more reckless. Zara never learned. Those two will get themselves in trouble, one day. Rina's innocence and Stock's naivete worry him; idealism without common sense is a recipe for destruction. Even middle-aged Luther, with his direct simplicity, is in danger of seeing too narrowly.
Children, he calls them, teasing -- but he does not use the word unthinkingly.