承诺的承诺是背叛曾经的曾经是回忆
[chéng nuò de chéng nuò shì bèi pàn céng jīng de céng jīng shì huí yì]
Promised pledges can turn out to betray what has been past and all those things only left behind are just mere recollections. This implies a feeling where a broken promise turns the previous cherished events into nothing but bittersweet memories.