Because

“Once a love loses the ability to be jealous in any capacity, they lose the ability to love in depth and whole.  Lust, jealousy, infatuation, daydreaming the perfection of that love are all ingredients for the truest of love.  For this love to be solid and un-breaking, both must sacrifice regular emotions and succumb to the feelings that their love is special beyond all boundaries and must be treated as such.  Without maintenance from the heart the building will soon fall into disrepair.”