You must try to quickly forget.

你必须试着赶快忘记。

I only hope you will quickly forget this weakling who lacks the courage to be frank.

我不敢求你谅宥，我只希望你快忘记我这个软弱、没有勇气的人。

You quickly forget about that beautiful guy you kept locking eyes with in the cappuccino 4 line.

你很快忘了买咖啡排队时让你痴痴凝望的漂亮的男人.