I read P&P once in high school and I thought it was cute but than when I reread it as an adult college student, and the story really made an impression.

In fact, I was able to take a 400 level class where we'd look at an author and all of their works through the society and time period they lived in and it just so happened Jane Austen was the author and we got to read all of her novels, her short story and two of her unfinished novels.

So, to answer your questions, I was twenty five years old when Pride and Prejudice impacted me :)