to learn the "doctor words"
for your private parts.
Lots of families use their own special words for private parts. That's okay! It's fine to use those at home. But sometimes, if you have a problem, you might need to talk to a trusted adult about your private parts. And if they are not in your family, they may not understand your family's special words. So that is why kids should know the kinds of "doctor words" that all adults are likely to understand.