I mean the oldest, the one you had when you were youngest.

I've got two, both from about the time I was 4 or 5. I don't remember which came first, so in no particular order they are:

1) I am in my room playing with my cousin. Suddenly, one of my eyeballs falls out of its socket and rolls away. I pick it up but I'm not sure how to put it back in my head. I ask my cousin for help but he doesn't know either. So, I go around the house asking my whole family for help one by one. It's around Thanksgiving so there's a lot of extended family there, but everybody's too busy to help me.

2) Balls of fire are falling from the sky like rain. My whole family has to go inside and seek shelter. The sky's gone black and it looks like the world may be ending.

Those two have always stuck with me.