I love it in this scene where JA describes Henry walking over to speak with Mrs. Allen and Catherine.

...making his way through the then thinning rows, spoke with like calm politeness to Mrs. Allen and her friend. Not with such calmness was he answered by the latter: “Oh! Mr. Tilney...

I imagine Henry getting slammed with this emotional response and thinking how unexpected it was. He probably thought she would calmly give him some weak excuse about why she went off with her other friends without leaving them word but what he got was so much more. How could he resist! Especially after being told by a young lady that she would have jumped out of the carriage and run down the street to spend time with him.