How do the Joads, especially the children, show their ignorance of “modern” conveniences?

The Joad children are completely ignorant of modern conveniences, something that makes them all the more endearing. Ruthie accuses Winfield of breaking the toilet, which of course, he hasn't. They simply don't know what it is, or what it's used for. Showers provide another moment of humor, as do the sinks. Even Ma shows her ignorance of these modern pleasures when she accidently uses the men's restroom.