丢三丢四不丢你三生三世只爱你
[diū sān diū sì bù diū nĭ sān shēng sān shì zhĭ ài nĭ]
It means 'Always forgetting things but never you; loving you eternally across lifetimes.' The user pledges their eternal love, indicating they might forget everything else, but they would always remember their love for one person over multiple lives.