This statement helps us understand how valuable even the smallest piece of Torah is. If someone helps you one time with something menial usually you would appreciate it, but not to the extent that you would actually "accord him honor". But imagine if someone gave you job or even cured you of a disease you would have tremendous appreciation and accord them honor whenever you would see them. This is what the Mishna is telling us in regards to the smallest teaching of Torah. It's great importance and value requires our appreciation and honor to the person who taught and gave us this. The Torah we learn is a gift that is more valuable than any material possession or gift and therefore our appreciation should be in accordance with that.

Shabbat Shalom,

Heath