Three biggest mistakes

In speaking with a friend about her son today, she asked me this:

In your twelve years of teaching, what are the three biggest mistakes that you see parents make.

I answered without hesitation:

1. Telling a son or daughter that "it's okay to defend yourself if someone has hit you first."  I inform my students to defend themselves with their feet by running away as fast as possible.  You never know what a person might have in his or her pocket.  As a kid, I can recall running into bullies...