Let's cut to the chase here — it's time to grow up. The world has way too many people in it for everyone to be so immature. Here are a few tips and tricks for both the people who desperately need to grow up and for the people who need to teach someone who desperately needs to do so.
Choose who you surround yourself with
Stop surrounding yourself with people who make you miserable more than they make you happy.
Example: Don't let who you've been hanging out with regularly bring you down or make you act like anyone but yourself. Rather than sticking around and continuously trying to fit yourself into their mold, cut them out of your life. There are people out there who will love and appreciate you for you, and that's where you'll find happiness.
Choose your battles
You know those pesky little things you have to deal with that come up in every day life? Yeah, those aren't going anywhere. We are only human. We don't have the physical, mental or spiritual capacity to control every little thing at once and we certainly don't get to have everything go our way all the time. Ask yourself what really matters before you freak out about every little thing.
Example: Your roommate gets hot easily, but you're cold natured. Instead of nagging each other or passive aggressively changing the thermostat after your roommate goes to bed, just sleep with an extra blanket on your bed or sleep with socks on. There are bigger things to worry about.
Realize that you'll win some of those battles, but you'll lose some, too
Things will go well sometimes but other times, things won't work out so nicely. You have to realize that you win some and you lose some, and that's totally normal.
Realize if you can't change it, just accept it
There are some things in this world that are simply out of your control. Learn to be OK with that and learn to stop micromanaging.
If you can change it, though, change it
Some things in life, though, you actually can do something about. So do something about them. Stop complaining and change something. Being proactive is a lot more productive than being apathetic.
Example: If you're so unhappy about your grade in a class, here's a thought: Work harder. Put forth some effort and change your grade, don't just sit back and complain about it.
Stop playing victim
The world doesn't feel as sorry for you about every little thing as you seem to. Every single person in this world has his/her own mess to clean up and his/her own obstacles to get past. Stop pretending you're the only person with a lot going on and stop expecting everyone else to feel sorry for you all the time. Start counting your blessings and focusing on the positives, that's one way to make your issues seem significantly more bearable.
Example: You got a B on a test that you really thought you aced, so naturally, you're moping around like the world is crumbling at your feet. Do you honestly think that kid in your class on the verge of failing out of college is going to feel sorry for you? Or what about the person you went out with the night before the test (instead of studying)?
Get over it and move on
As if I haven't made this very clear yet: Things do not and will not always go your way. You can't change that, I can't change that, your mom can't change that, your friends can't change that. Dwelling on the things that don't turn out the way you want them to is poisonous. Move on – you'll make yourself miserable.
Focus on yourself more often
No, I'm not telling you to be selfish. I'm telling you to spend less time analyzing other people and picking them apart, but rather spend more time figuring out to better yourself. Don't fall into the comparison trap and don't fall into the habit of belittling other people to make yourself feel better.
Stop subtweeting and making Facebook posts as a dig to someone else
This is just about the most immature thing you could possibly do. Passive aggressiveness only pisses people off even more than confrontation does. If someone is bothering you enough, explain to them (calmly) that you're upset and work through the issue, or just keep quiet and move along with your life. Also, life hack: Don't say anything online that you wouldn't say to someone's face.
Example: If your roommates forgot to take the trash out or left their laundry in the dryer overnight, move along with your life. Don't stoop down to the level of those people who complain about every little thing online (read: publicly). Your roommates will find out and it will make them want to piss you off even more.
Stop trying to make things work that clearly don't work
If you just can't seem to mend a broken relationship or come to terms with something that has upset you, no matter how long or hard you've tried, just stop. I'm not saying to give up because you're lazy, I'm saying to surrender the stress of trying to fix something that clearly doesn't want or need to be fixed.
Example: If your long term friendship has been on a slippery slope for two years now, but you have several other people in your life that respect you and make friendship effortless, then maybe it's time to let go.
Respect other people's opinions
It's amazing to me that people don't understand this by now: Every person is entitled to his or her own opinion. Every person in this world has their own story, their own upbringing, their own beliefs and their own way of viewing the world and its issues. If you don't agree with that person's opinion about something, just shut up and move along. You have your opinion and other people have their own. If you expect people to respect your opinion, then you best respect theirs.
Example: You're the only conservative person in a classroom full of liberal people. You voice your opinion as to who should be the next president and you get yelled at by everyone in the room for your beliefs. But, when other people in the room voice their (opposite) opinions about who should be the next president, you sit there quietly. Why? Because they have the right to their own opinions and yelling at them for it being "wrong" is not the way to get them to change their minds.
Be nice to people
I mean really, it's not that hard to do. Pro tip: The nicer you are to people, the further you'll get in life and the more genuine relationships you'll have.
Let go and let God
By now, you should be able to gather that you simply cannot handle every aspect of life at once. Also, you can't expect other people to carry your burdens too because they all have their own burdens. You know who is more than willing and able to help, though? God. Let Him help you out.