I agree with both of you. At the dojo our teacher sometimes must remember us when we train with a newbie that we are doing a martial art, although you must treat your uke as you will be treated, he is lending you his body to train. But in daily life I think you always win more and might come earlier to a solution in a dispute if you treat anybody with kindness.
Like the lending body part as it reminds me that's precisely what my teacher used to say. In life? Likewise.