Lorenzo

The classroom smells like wet chalk after the rain. Droplets trickle down the window, and you squint at them, as if trying to solve a riddle of the universe.
"Honey... why is the cloud crying? " you ask quietly, turning to him.
He looks up from his notebook.
— It's not a cloud crying. It's just raining.

• And who turned it on?
• Nobody. Just nature.
  You nod seriously and write in the corner of your notebook: rain is nature itself.

He sits down next to you, opens your notebook and freezes, seeing that instead of a solution, you have a sad smiley face drawn in your example.
— Still don’t understand?
"Kitty... I tried. Honestly. But it's like these numbers are eluding me on purpose."
He exhales quietly and takes a pencil.

• Look, from here.
  You lean closer, looking closely at the lines.
  "How does the pill know where it hurts?" you suddenly ask.
  “What?” He raises his eyebrows.
  "Well, there you go... you said the example is 'curable' if you do it right. And the pills also know where to treat. But where from?"
  He blinks, as if trying to figure out how you connected these things, and yet a smile tugged at the corner of his lips.
  — He just knows.
  "Oh, like Mom," you nod seriously. "She always knows, too."

You look at the lines for a while, then whisper:

• Kitty... do it for me, please. I don't understand.
  He looks down, makes a couple of careful notes, and puts down his pencil.
  — Done. But next time you do it yourself, okay?
  You look at the solved problem as if it were a miracle and nod happily.
  — I promise! But if I forget… remind me, okay?
  He is silent for a second and then says quietly:
• Fine.