1. Grammar
If you're over 18 and can't properly construct a sentence...we have a problem. I understand that not everyone has strengths in English, but when every single word is misspelled, someone went wrong somewhere along the line. If you're over 30, we have a major problem. Facebook has probably worsened this situation because that's where the majority of my pet peeves come from. If you are going to post a Facebook status, take the time to spell out the words. It's really not much more work. I don't want to see "u" or "r" it's "you" and "are." You're not cool if you spell "phone" as "fone" either. Stop. A final pet peeve in this category is: If you're going to curse online, at least spell it right. I get that I don't follow all grammar rules by any means, but I write intelligently (the majority of the time) and I don't spell every single word wrong. (Let's be honest, my biggest grammar error is pronoun-antecedent disagreement and if I'm thinking about it, I avoid using it).
2. Facebook statuses about OTHER PEOPLE
I hate reading the drama of Facebook oh so much. I've tweeted about people before, but there's a difference, I'm not trying to stir up drama or anything, I just need somewhere to say it and it's not Facebook worthy. Don't post about others knowing that they will see it just to start drama. It's pointless. It's not worth my time to glance over your post, or anyone else's time as well. I get positive statuses about others, they're cool, but when people post negative things about others, that's when we have a problem. If you're over 30 and trying to start drama on Facebook, I really question the direction of your life. If you have nothing better to do than start drama with younger people on Facebook, you really need to reevaluate your life.
3. The numbers 1, 4, 7, 8, 11, 13, 17, and many more.
4. When someone calls you and you call them back within 2 minutes and they don't answer.
If you're going to call me, be waiting for my call back, especially within the first 10 minutes after you call me. I don't always answer my phone (It's usually on silence) and when I call someone back, I expect them to answer. If I call you back within 2 minutes, don't answer and say you're busy. How much busier can you be now than you were 2 minutes ago? I don't buy it.
5. People who text in class
I've texted in class before and it's only for important things and I don't make a habit of it. I don't sit with my phone during class, I put it in my backpack and don't look at it unless there's a break or I need it for some part of class. You're in class for a reason; to learn. You have all kinds of time to be on your phone, so put it away. You're taking away from my educational experience and yours and we're both paying for the experience, so...let's not do that.