Well, it’s not as if because someone chooses to love in a given instant that they are sure to choose to love in the next hour, or the next day, or the next year. “True love” in the sense of a being a choice is limited by time and space (unless you are talking about Christ.)True love is not a choice, not at all. If it were, there would be no broken hearts.
That’s the whole point of love being a choice. You have to choose to love second by second, minute by minute, day by day, week by week, month by month, year by year… It’s not a once and for all thing. It is a series of ongoing choices to act for the good of another.
That’s why when one picks a spouse it is important to pick someone who one will want to continue choosing to love.