Lost love is still love. It takes a different form, that's all. You can't see their smile or bring them food or tousle their hair or move them around a dance floor. But when those senses weaken another heightens. Memory. Memory becomes your partner. You nurture it. You hold it. You dance with it.

This quote is saying that even though a person has lost their romantic love, that love still exists. Although the physical manifestations of that love are no longer available, like being able to see their smile, bring them food, tousle their hair, or dance with them, the memory of that love will endure. That memory can act as a surrogate for the physical parts of the relationship and can be treasured and cared for as though it were still there.