I was hit from behind by a teenager years ago. Like you, I was fine at the time, but so sore the next day. The girl who hit me was very sweet and nice. It wasn't her fault. Yes, she shouldn't have been following so closely, but someone pulled in front of me to take an exit at the last moment and I had to slam on my brakes. She just barely tapped me (years before air bags). We exchanged information and she went home. A few days later, I called and her mother answered. I was calling to see how her daughter was -- was she as sore as I was. Well, she went off on me! She ranted and raved like I had set her daughter up to rear end me! I listened for a few seconds hung up the phone after saying "Have a nice day" in the same tone you would say "F-you".