Love cannot endure indifference. It needs to be wanted. Like a lamp, it needs to be fed out of the oil of another's heart, or its flame burns low.

This quote is saying that love cannot exist without a mutual willingness to give and receive it. Love is like a lamp, in that it needs to be constantly “fed” or fueled with the warmth and affection of another person. If it is not, it will die out, like a lamp flickering out when it is not being fed oil. In order for love to survive, it needs to be wanted, cared for, and fed constantly by the hearts of two people.