Your 20s are a curious time. On the one hand, you're no longer a kid - you've got stuff like bills, rent and booze to pay for.
But on the other hand, you're a tiny defenceless kitten in the world of real adulthood, and you've still got a whole lot to learn.
Thankfully, a bunch of people on Reddit have imparted their wisdom to us younglings.
So what is it we need to learn before 30 rolls around?
1 Only a few of your friends are true friends
Sure, you may have a great gang of people to hang out with. But when things go down the shitter, you'll notice that a select few people are there standing by you.
These guys are your real friends. Hold 'em close.
2 Lifestyle inflation is a bitch
In other words, don't spend more money the moment you earn more. It's easy to do, but much harder going the other way.
3 Appreciate every day you have with your family
They won't be around forever.
4 Take up exercise now
And perhaps a sport, because it's way harder to get into when you're older.
5 You are not invincible
When you're young it's easy to feel that nothing will stop you.
But it will. Don't drive like an idiot, and quit risking your physical safety.
6 Do stuff that makes you happy
Rather than stuff that makes you look cool.
7 Go to the dentist
Teeth don't heal, and once you've fucked them up, you've fucked them up.
8 Don't lend anyone money
Or only lend what you're prepared to lose.
9 Pride does nothing
If you don't say good morning to your boss because you think they're a dick, you're not doing yourself any favours.
10 It's okay to ask for help
Don't try to man or woman up to get through it. It's a waste of your time to suffer needlessly.
11 Friends come and go
And how you define what makes a friend will change.
12 Debts and weight...
...They're easy to gain, and hard to lose.
13 Save some money
Even if you just put £5 into a bank account a month, £60 could get you out of a sticky situation in a year.
14 Not all family are blood relations
Family is what you define it to be.
15 Don't prioritise someone if you're their backup plan
If only one person is making all the effort in a friendship, it's probably not as good a friendship as you thought it was.
16 Owning things won't make you happy
That £40 cardboard cutout of Jeremy Kyle may make you chuckle, but do you want it? Really?
17 Don't whine too much to the people around you
When you whine, you're forcing the people around you to become responsible for giving your life meaning, which isn't helpful for any of you.
Note: this is different from asking for help, or having the occasional vent.
18 Stuff gets easier the more you do it
Even if it doesn't feel like it at first.
19 30 will come by fast
The day you thought "one day I'll do such and such" will become 10 years ago quickly.
20 But life doesn't end at 30
Just in case you didn't realise.
Feature image: Ronna's blog