That's when it hit me...

Meaning

Describing a sudden realization.

Examples

• John: I was driving home, lost in thought...
• Alice: And?
• John: Suddenly, I remembered the meeting! <b>That's when it hit me</b>...I forgot the most important document!
• Alice: Oh no! That's terrible. I bet you felt it immediately, right? <b>That's when it hit me</b> too, once you said that.