This quote means that when a person experiences a profound or passionate love, it alters them in some way and they may never be the same again.The emotion of love can be incredibly powerful and life-changing even if the love relationship itself doesn’t last. It can be so powerful that even after the love affair is over, someone may still feel the effects of it long afterwards. The quote suggests that feeling such powerful love can be likened to suffering a serious illness from which a person may never fully recover.