若世上只有你一人我定对你加倍珍惜
[ruò shì shàng zhĭ yŏu nĭ yī rén wŏ dìng duì nĭ jiā bèi zhēn xī]
If There Were Only You In This World, I Would Cherish You Much More suggests deep appreciation and adoration for someone in an ideal world where nothing else would distract from their bond, indicating that this individual places a high value on their unique relationship with another person.