难得情深奈何缘浅
[nán dé qíng shēn nài hé yuán qiăn]
'Rare is the profound affection when fated ties are shallow'—It suggests that it's rare for a person to truly fall deeply in love; even if two hearts meet, fate often doesn't bring enough encounters or opportunities, leading to a sense of helplessness about the transience or insufficiency of true feelings.