Out of the blue
Suddenly and unexpectedly
If someone does something or something happens out of the blue, it happens suddenly and surprises you because you didn't expect it.
Late last summer, out of the blue, Sue announced she was getting married and leaving her home country soon. We were all shocked to hear that.
We had been told it would be sunny all day, so we went hiking. However, it started to pour (rain heavily) out of the blue in the afternoon.
with my best regards
Feel / Look like a million dollars
Feel very happy.
Look very attractive
If you feel like a million dollars, you feel extremely good, often because you are doing something luxurious.
I felt like a million dollars in the tuxedo at the President's reception yesterday .
Look! She looks like a million dollars in that gorgeous dress today.
Not hold water
Not seem reasonable or correct.
If something such as an arguments or a statement does not hold water, it is not reasonable or true.
Their arguments against the government's foreign policy simply don't hold water.
Most agree that the mayor's reasoning for not taking an action doesn't hold water anymore.
Be on the tip of someone's tongue
Cannot remember something such as a word or the name of a person although you think you know it and you will remember it soon.
If you say something is on the tip of your tongue, you mean you can almost remember it but not right away.
What's the girl's name there?
Once in a blue moon
Rarely, almost never
If you say something happens once in a blue moon, you mean it happens very rarely.
A blue moon is the second of two full moons in the same month, which happens rarely.
He has a very nice car, but he drives once in a blue moon.
Wait a second, it's on the tip of my tongue. ... Yes! Her name is Joanne.
A: Does your husband cook for you?
B: Oh, yes, once in a blue moon!
The teacher asked them a question. The answer was on the tip of his tongue, but another student raised her hand and said it first.