How do you make friends as an adult

What the hell! I feel like Forest fucking Gump when i try to make conversation with people waiting in line. They act like I just told them something amazing and then turn around and pretend I don't exist. I dont understand why its so weird to talk to you we are waiting for the same thing we must have at least one thing in common. So what you have big breast that's not why I'm talking to you. Ok well you don't know that's why. Ok well good guess...this time but still.