Summoning People

No matter how hard I try, I can't seem to bring the people of my choice into my dream. I'll keep imagining a certain person being around the corner, behind a door in a different room, anywhere. It just won't work. I know that you need to believe in things to make them work, but when you failed to do it a hundred times, you kinda stop believing :/. It's a vicious circle, I already know it's not going to work thus it's impossible for me to really believe it. At first I thought it didn't work because it's something that's impossible in real life, but I learned to fly in a matter of minutes and I can put my hand through a wall without trouble (I sometimes use that as my reality check) Any help?