I was teaching a guy how to punch stuff in school
Why were you teaching him to punch stuff?
He was a little bit frustrated and he wanted to punch things.
Teaching someone how to release anger in a healthy way is good. Just make sure he does not hurt his hands doing so.
He really needed the help, he always had pent up anger.
It is great you took this upon yourself to teach him this. Helping out others is a nice thing to do and others will recognize you.