Self Interest?

“Interest never sleeps nor sickens nor dies; it never goes to the hospital; it works on Sundays and holidays; it never takes a vacation; it never visits nor travels; it takes no pleasure; it is never laid off work nor discharged from employment; it never works on reduced hours. … Once in debt, interest is your companion every minute of the day and night; you cannot shun it or slip away from it; you cannot dismiss it; it yields neither to entreaties, demands, or orders; and whenever you get in its way or cross its course or fail to meet its demands, it crushes you.” J Reuben Clark