Assumptions of symmetry...another truism?

Something is wrong. I am finding too many new truisms. Consider: "I was nice to her but she was not nice to me". What is the underlying truism?
NO: it is Truism 4 applied to a known relation like "nice to".
Update: Hun? This example is a challenge.
Point #1: subjects have factoid structure and when factoids are violated it warrants using "but". So for example "I went to watch the sunset but it was cloudy".
Point #2 is that the symmetry of a relation is not a factoid but something else. You could spin it as an example of Truism #4C, where there friendship between two people is regarded as a single entity with two attributes being connected by that truism. One attribute of the friendship is the "nice to" in one direction; the other attribute is the "nice to" in the other direction. In this case the symmetry is the assumption on similarity of two different attributes of the friendship.
NO! Truism 4 says relationships remain the same, the "nice" relationship is an example, where we are swapping the 'from'/'to' roles in the two mentions of the relationship.