爱到深处心必凉
[ài dào shēn chŭ xīn bì liáng]
Translated literally, it means “Love too deeply and one’s heart inevitably becomes cold.” It expresses the notion that after loving too deeply, one’s heart eventually grows cold out of pain or self-protection. There might be some sorrowful history behind this user's experience regarding intense feelings turning bitter over time due to disappointments or betrayals.