15 people share the hardest lesson they've learned as an adult.

Whether you're 15 or 55, growing up is tough.

There are so many complicated nuances to navigating the world as an adult, and most of us weren't in the least bit prepared for them.

Even with the best parents and the most thoughtful temperament, you're going to hit some tough bumps in the road that you never could've foreseen.

Luckily, we don't have to learn everything through experience. Listening to the hard-won lessons of others is a great way to soak in more knowledge while forgoing some of the pain.

In a popular Ask Reddit thread, people shared the hardest lesson they learned as an adult, and you might find some fresh or familiar wisdom in here.

1. From Background-Guard9241:

One best friend is better than multiple acquaintances. Quantity does not equal quality.

2. From 0bi-What:

No matter how much you love someone you can't just make them love you, just as you can't make yourself love someone no matter how hard you may want to. And life is not fair.

3. From Throne-Eins:

Chronic illness can destroy everything you've ever worked for, and it can happen to anyone at any age.

4. From IllustriousSignal575:

Bad things happen to good people without reason or explanation.

5. From Blonde_rake:

That the person who hurt you, can’t make the hurt go away. People go back to their abusive partners and families over and over again hoping for resolution or closure. They can’t give it to you, they won’t make the pain go away.

It’s just going to be painful. The sooner you stop going back, the sooner the pain will heal.

6. From Tough_Stretch:

That you don't have to remain close with anyone just because you were close with them as a kid, or because they're your family, or because you've been close for a long time.

People change, and also people do things that irrevocably change the relationship or even destroy it, regardless of whether you forgive them or not.

For instance just to give a single example, it took me a really long time, simply out of misguided loyalty, to finally ditch a childhood friend who became a terrible person over the years.

He caused me a lot of problems that could've been easily avoided if I'd recognized that I didn't owe him any loyalty and simply walked away from that 'friendship' years earlier.

I had been putting up with a complete a**hole who had replaced the kid I had been friends with out of loyalty to that kid that no longer existed and hadn't existed for literal decades.

7. From Back2Bach:

Friends that you always thought would remain close often drift apart over time - sometimes never to be heard from again.

8. From CynicalGoodGuy:

Time passes faster and faster with each year. If there's something you want to do in life don't wait if you do you might find 5 years have passed without you doing anything.

9. From oneofyrfencegrls:

Other people can and will make the worst decisions you've ever seen. Even when they have the capacity and resources to make good decisions, they will not. You cannot help them. They have to die on their own.

10. From Turbulent-Shake4741:

Most problems are ones you have to face alone. You learn there isn’t going to always be someone there for you and to help you, and that yourself is really all you can count on.

11. From go-with-the-flo:

It's not always going to go the way you pictured it, or the way they told you it would. After years of dating and searching for the right person for me, I found him. Awesome, life goal: achieved. Then he died of cancer.

A couple of my friends are facing infertility challenges, meanwhile, so many others are having babies with ease all around them. This isn't how it was supposed to go, and it's tough to accept that you don't get the life that so many have.

12. From habofi2125:

When searching for a job, “it’s not what you know, it’s who you know” is true more often than not.

13. From guess_again255:

As soon as you can afford to start putting money away, start to put money away. Before you move into a better apartment, start eating out more, buying nicer clothes, etc, you need to pay yourself first.

Until you can regularly pay yourself, you can't afford to start upgrading other parts of your budget.14.

14. From JayLuMarr:

In this world, many people will prey on your kindness and use it to take advantage of you.

15. From farrenkm:

You need to take care of your mental health. Just as we're supposed to get physicals every year, we should get mentals every year. I've had a cascade of things hit in the last 16 months.

It wasn't triggered by events from childhood (I'm middle-aged), but the result was a diagnosis of anxiety (among other things) stretching all the way back to childhood, anxiety I didn't know I had.

Anxiety that, about 2.5 years ago, caused me a medical emergency that resulted in me permanently losing vision in an eye. Mental health is no joke. Keep it in check.