总会有一天我会忘记你，你和其他人快活的的时候，别告诉我。

I will forget you in a day . when you merry with other. don't tell me

我知道有一天我会忘记你我没有期待我没有悲伤我只是知道了而已。

I know that one day I will forget you. I don't have anticipation.

有一天，我会忘记你。我没有很期待，也没有觉的失落。我只是知道，有那么一天。

I will forget you one day. Neither do I expect, nor am I getting down. I just know the day will come.