Parents love their children, and will assiduously protect them against great dangers.

So something like this:

There are some words we never say, as it is very dangerous. One starts with "shy" and ends with "tan". Never say that word.

Of course, some kids will be smarties

"is 'shytam' okay?"

"Is 'thytan' okay? What if a lisping person says it?"

"If I had a friend called Tan, and he was feeling shy, could I say 'don't be shy, Tan'?"

This is the all similar to roads in 21C. Some inquisitive kids become road kill. In WoT, some become DF. It's evolution.