To give you more context, the movie is about these 2 people in NYC who only knew each other through an internet chatroom, and had started emailing each other, becoming fairly close. They eventually decided to meet, but Tom Hanks' character was the second to the meeting, and realized they had met IRL a few times, but not on the best of terms. He then spends the rest of the movie trying to become the friend IRL to Meg Ryan's character that he was online. Culminating in them agreeing to met again, where this time, he would be there first and she'd realize what he had months earlier.
I'm not saying it's a perfect fit, but there is some similarity there with Mandy and me, and if I saw her IRL, I'd recognize her, but she wouldn't realize who I was. I do also really like that movie.