The contextual and memetic aspect of what constitutes a "person's self interest" far outweights the person's actual decision and the individual actor cannot be removed cleanly from the wider discussion envelopping what this "self-interest" even is.
The "law" and its detterence logic shapes what "self-interest" is. Talkibg heads shape your understanding of reality and anchor what your self-interest is and means.
Nobody has self-interests in a vacuum.