Dec 25th: pinpoint

When did you decide that?
I can't really pinpoint the time.

From when did you love to play soccer?
I can't really pinpoint the time.

When did you decide to study abroad?
I can't really pinpoint the time.

Dec 13th: polish

I've completed my first draft of SOP.
Even though it contains what I want to say, sentences are not polished.

Dec 10th: on cloud nine

I have finished my final exam, so I'm on cloud nine.

on cloud nine: very happy!

Dec 7th: come out ahead

Listen attentively. You will come out ahead in the coming week.

come out ahead: to end up with a profit, benefit, or advantage.

It was a tricky deal, and no one came out ahead of anyone else.