Do you believe that dreams have meaning or not and why?

Im sure that they do but i just dont know what the meanings may be. My oldest brother died from a medical condition. He lost several friends due to violence. So i had a dream one day that all of them were knocking on the door saying let us in. I was peaking through the peephole. I had been to all of their funerals. And my phone was ringing in the dream so i anwered it. It was my brother and he yelled into the phone "Open the door! " And then i woke up. It was creepy. I have no idea what it meant.