"如果一个人只爱一个人而对其他同胞漠不关心，他的爱不是爱，而是一种共生的依恋或一种扩大的自私。"

Simplified Meaning:

When someone feels love only for one person and doesn't care about anyone else, it's not real love. It's more like they are clinging to that one person for their own needs and not truly thinking about the other person's well-being. For example, imagine someone who has a best friend but treats everyone else rudely. This isn't real friendship; it's just using that one person to feel good or secure. True love or friendship goes beyond just one person and shows kindness and empathy to others as well. When you genuinely love someone, you generally develop a sense of compassion for others too. So, to apply this idea to your life, try to be kind and considerate not just to your closest friends or family but to everyone you meet. This way, your love is genuine and not just about making yourself feel good.