Mom: “That haunted house sure was scary! Are you okay? Not too scared?”

Daughter: “It wasn’t that scary! They weren’t real ghosts!”

If something was less scary than we expected, or not as scary as someone said it would be, we say it wasn’t “that scary”. You can use this pattern with other adjectives, too. “The curry wasn’t that spicy.” “Bob recommended this movie, but I didn’t think it was that good.”