That might have explained the crustiness of Charlie's answer.

这令查理的回答变得生硬起来。

Once I broke through my initial crustiness and got into the habit, it even became a game: Can I make this grump open up?

一旦打破了自己原来粗鲁的举止，养成这个好习惯，甚至把它变成了一个游戏：我还能让脾气再发作吗？