Book 15 defines true love with unusual sharpness: it gives, gives again, and then forgets what it has given. Love becomes false when giving turns into bookkeeping.
That makes true love more than sacrifice. It is the refusal to protect the ego through remembered debts. It keeps moving outward rather than circling back to self-justification.
This is sermon-worthy because many relationships fail not when giving stops, but when giving becomes moral accounting.