the shock of (one's) life
An extreme and sudden sensation of shock, surprise, or fear. Often used after the verbs "get" or "give." Seeing the car swerve right in front of her gave Mary the shock of her life. I got the shock of my life when I noticed someone standing right behind me. Little did he know that he was in for the shock of his life when he crossed the threshold of the old mansion.
*the shock of one's life
Fig. a serious (emotional) shock. (*Typically: get ~; have ~; give one ~.) I opened the telegram and got the shock of my life. I had the shock of my life when I won $5,000.