Adults and other humans know of umbrellas. You see them. I've seen them. I've seen some students carry them because there's always a decent chance it will rain.
I can see one end of my campus from the other end, well, if I'm on the second floor of a building. It's 3500 students. We have residence halls located NEARLY in the middle of campus.
Today it started raining around 8 am, which is a little early.
At my 10 am class I had 12 of 30 students arrive, all perplexed, dripping, stunned, really. Their looks of incredulity were precious and a little funny. They shook themselves like dogs and complained about the nuisance.
The other 18 students? Well, 4 came in late and 4 came in REALLY late.
The other 10? They stayed home. They stayed in their dorms.
One wrote to me, "It doesn't like like its every gonna stop raining."
Others wrote, too, but with fewer errors, but the message was clear. It's raining. There's no way to get to class.
No flooding. It was showers. No puddling. There are concreted paths from every building to every other building. There are overhangs over all the buildings. You could, without an umbrella, scamper up one side or the other of campus under building overhangs about 50% of the time.
Spankings. This is all I'm thinking about. I don't believe any of these children got enough spankings.