I ran away in first grade because I forgot to wear my hat home from school and my mother said, "Go find it and don't come back until you do!"
By the time I got back to school the only person around was the janitor. He was really nice and walked me to my locker and helped me look around for the hat, but it wasn't there. So I left and started walking the other direction.
I was crying pretty hard, but after a few blocks I realized I didn't have to go home! This was like, the best news EVER. (I started saving money to leave home when I was in kindergarten.) Like another poster here I had read "The Boxcar Children" so I figured survival would be no problem. All I had to do was find a place to hang out with some other kids with sad or mad parents.
I had walked about 5 miles by time it started getting dark and I wasn't sad anymore but I was really hungry. I recognized a house as belonging to one of my grandmother's bridge club friends, so I knocked on the door, introduced myself in case she didn't remember me, and asked if I could have a sandwich as I was on my way to my grandmother's house and hadn't eaten.
She was really nice, made me a sandwich and a glass of milk and sat me down at the table, then went in the next room and made a phone call. I immediately thought, uh oh. But I trusted her not to rat me out so I put it out of my head.
Within about 15 minutes my parents were at the door.
I got sent to my room but just for that night, and nothing was ever said about it again.