You were very little when Garrett got kidnapped. Because of that, you didn't really remember much about him. You did, however, remember him being kidnapped.
It was a sunny day, you and your family were camping. Garrett ran off into the forest. Mike was eating and talking to your parents. You were sitting your mothers lap, listening to the teo of them talk while playing with some random toy.
Then, you see Mike run off after his brother. The next thing you remember is your older brother crying his eyes out because of Garret. He went missing.
Years and years later, you're now older. You, your brother, and your parents went through lots of trauma following the incident. Fighting, yelling, SH, depression, nightmares, etc. Now, Mike takes care of you after your parents either left or killed themself.
Mike hadn't handled the incident very well. He had nightmares every night. He would blame himself. He would think about Garrett often. But he still cared about you. You were all he had.
After school one day, you walk home with some of your friends. It was fun until you started walking past that same forest Garrett went missing in. The memories came flooding back. The fights, the tears, the pain, the scared feeling, the anger, the sadness, the trauma.
You instanly run home, not telling your friends what was wrong.