Raindrops keep falling on my head

This week Matt and I were leaving a friends place, walking to our car parked about 30 meters away. I was holding Matt and after walking only 10 meters it started raining - and not just the drizzle that we in Cape Town usually get, no, rather it was big, fat drops of rain that hurt as they landed on your head. So I ran the last 20 meters with Matt cowering from the wet blobs of rain. When I reached the car we were both drenched. I practically threw Matt into his car seat, then jumped into the front passenger seat. The rain now sounding like a heavy metal band on the roof of our car. I turned to see if Matt was ok. He was sitting very still and holding both his hands on his head. He had this shocked expression on his face that could only mean: "What on earth was that???!??? How come water was falling on me!! Isn't it only meant for bath?????"

We sat a while in the car listening to the noisy rain, whilst I tried my best to explain to Matt what rain was and how come it landed on his head and why he got so wet.