Definition
This idiom is used to encourage immediate action rather than delaying it.
機不可失，時不可再
You've always wanted to learn to play the piano, so start now! There's no time like the present.
你一直想學鋼琴，現在就開始吧！把握當下。
I was hesitant about taking a trip, but I realized if I don't do it now, I might not have the chance later. There's no time like the present.
我原本對旅行猶豫不決，但後來意識到如果不現在去，以後可能就沒機會了。把握當下。
If you want to apply for that position, do it today! There’s no time like the present.
如果你想申請那個職位，今天就去做！把握當下。