I can't stand the response: "I told you so."
A: "I got hit by a car."
B: "I told you to look both ways before you cross."
A: "My boyfriend broke up with me."
B: "I told you he was a jerk."
A: "I have a cold."
B: "I told you to take your vitamins."
It's not helpful or supportive. It makes the situation worse. So you know what? Instead of stating that you're right and I'm wrong when I'm already dealing with some heavy issues, how about you say something sympathetic? Be a good friend. Listen. It's not that hard.
But people just always want to be right. Then they feel better about themselves.