I had nightmares all the time when i was younger. For every normal dream, I'd likely have 3 nightmares to pair to it, and I remembered the nightmares easier. There are 2 that stand out to me, and I can't choose between them.
The first was a reoccurring nightmare. It would be me and a group of my friends all hanging out at night by the school, when this giant, purple shadow hand would come floating towards us. I was the only one who could see it, and I tried to get my friends to leave and run away from the danger. Usually, all of them would just laugh and ignore me. The hand's nails would extend and impale everyone who didn't run. Sometimes, I'd have one or two people believe me and run, but they'd never be with me when I reached my home. I'd turn all the lights on and run to the kitchen, because that's where the phone was. I don't remember dialling a number, but I'm suddenly talking to my mom and telling her what's happening. Oddly, she'd be terrified for me, but knew exactly what to do. I was told to stay in the kitchen, keep the light on, and don't move. Then the line would go dead and I'd hear the door open. I'd usually wake up about there.
The second nightmare that I remember fully and clearly. It starts with me, younger, walking to school... or maybe home from school... I just know that I had my school backpack. Suddenly the area would begin changing. Trees would disappear, it grew hotter and drying, and the pavement was replaced with sand. I think I was supposed to be in the Middle East. As soon as the last piece of my familiar town was gone, the sounds of war would suddenly be around me. Shouting, gunfire, explosions. But I couldn't see anything other than sand and sun. Even in the dream, I had no idea what was going on. Before I was able to turn around, or start walking forward, someone came up behind me, and forced me down, taking my backpack. I remember that bothered me... Anyway, they'd force me fully laying down, face in the sand, telling me things would be ok. To not worry. There's a really loud shot, and I can feel heat on the back of my head. Things go black around the edges, slowly moving inward until I can't see anything. I can't feel the heat of the desert anymore, and I can't hear the battle. I'm left in blackness in my dream. I woke up a few seconds into the blackness, terrified and crying.