I get that irrational feeling too sometimes. Like if I'm on the highway following a really slow car and I'm going to be turning left at the next road, I won't turn my signal on until it's too late for that car to turn left too. I know it's totally irrational to think the car in front of me would go out of their way to turn at the same corner as me just because they know I'm going to turn there and they want to annoy me.

Sometimes I'll get behind two cars who are driving below the speed limit side by side, and I can't pass. I'll think they must see I want to get around and one or both of them are doing it deliberately. Then I'll say to myself, "No, they're just in their own little universe, and they don't notice me back here." Then one day I heard a coworker laugh and say that she actually does that - drives slowly next to another slow car in order to prevent a faster car from passing. So, some do do it deliberately.