Why do I still remember these dreams from when I was 5? What do they mean?

one was where thete was somewhere with alot of ice and water. My family was on some ice thing trying to sail to this other big ice mountain thing. Though there were ice people( like white ice manicans) were just standing there, and alligators were coming after us. And the weirdest music was playing. Wow! Another was I was on my moms back and we were swimming through some cave through these weird water creatures. Another was I was driving in a car with mom on a bridge and I fell off the bridge( far actually) onto a beach but I didn't even wake up.