念念不忘只爱你恋恋不舍只想你
[niàn niàn bù wàng zhĭ ài nĭ liàn liàn bù shè zhĭ xiăng nĭ]
Describes unbreakable love and longing, conveying that despite the time passed, nothing else matters but their undying affection for that single person they loved or are still loving.