Definition
To pinch oneself means to do so, typically on the arm, as a way to confirm that something surprisingly good or strange is really happening and not a dream.
難以置信（好到或怪到不可思議）
She pinched herself to make sure she wasn't dreaming after learning she had been selected to participate in the Olympics.
得知自己被選中參加奧運會後，她掐了自己一下以確定自己不是在做夢。
They couldn't help but pinch themselves when they discovered they had won the lottery jackpot.
當他們發現自己贏得了彩票頭獎時，他們忍不住掐了自己一下。
He had to pinch himself to make sure he was really talking with his long-time idol.
他不得不掐自己一下，以確保自己真的在與他長久以來的偶像交談。