Easily get mad?

Well, this is not about me. About my friend. At least he's still my friend until some days ago. You know what? He's angry with me just because a normal thing, a small thing. That day, after class, there's an announcement from the speaker. And then this guy, who's used to be my friend, was talking with a loud voice with another student. Automatically, I said, "ssh..". But then this guy said "WHAT????", scolding at me. I just kept silent because I want to hear the announcement. After school, He glared at me with the way anybody won't like it. And he did another thing that won't make anybody feel happy, in other words: disturb me. Just the question is, am I wrong, just reminding him to be quiet because there's an announcement? Well, I just can't accept that he's mad with me because of such a small thing. And because of that, I lost a friend. He start the fight. I'm just fine with him, but if he want to fight, well, go on. I don't care so much. Like I will care.