Good advice is hard to find.

That's why we recently reached out across the Upworthy Facebook, Twitter, and Tumblr accounts asking you, our readers, what was the single most valuable piece of advice you've ever received. The answers ranged from funny to serious to heartfelt and emotional.

Below, however, are 17 of our favorites.

1. Don't complain about getting older: not everybody gets the privilege.

Over on our Facebook wall, Carol shared a short story about her husband of 21 years dying of cancer. Her story was filled with bits of advice about aging and relationships, and one line stood out: "Don't confuse intelligence with maturity."

2. On relationships — always appreciate your friendships.

This piece of advice comes from Rachel on the keys to a successful marriage. Over time, feelings may change for the ones we love, but so long as friendship remains a constant in our lives, it can work.

3. Keep moving forward, you'll make it.

This story from Ketanie tackles the aftermath of a serious car crash that left her in a coma. After she woke, she was told she might lose her leg and not walk again. She made it her goal just to move a little bit each day, and after months, she's back up and walking, able to take care of her girls once again.

4. Too often, we're too worried about what others think.

Sometimes we focus too much on what other people are doing, what credit other people are getting, and letting jealousy of these individuals bring us down. When those moments happen, it's good to put on the blinders and focus on what's going on in our own lives.

5. You can't control what others think of you.

Sienna shared this bit of advice, which has been attributed to probably close to a dozen sources (must be that good if everyone wants credit for it, right?). But it's true: You can't change what someone thinks about you. You can only change how you act and what you do. It's up to them to change their perception.

6. Unsolicited advice should be taken with a grain of salt.

Ever have someone just come up to you and start offering up advice about something you really didn't need anyone else's opinion on? It's kind of annoying. Instead of offering unsolicited advice, offer to help, instead.

7. There's no step too small.

Terri wrote that after she had her first child, a friend offered her this bit of advice: Too often, we try to do so much or we look at the things that need to be done and find they just seem so overwhelming. Life doesn't have to be so overwhelming. Just take things one step at a time.

8. You're your own worst enemy. Be your own best friend instead.

If you're anything like me, you're probably your own worst critic when it comes to, well, everything. I like to think of myself as a good friend to others, but I'm certainly not one to myself. Maybe if I put the same level of compassion into how I treat myself as I treat others, I wouldn't always feel so anxious.

9. Don't sweat the small stuff.

Patty wrote about a piece of advice her father gave her before she got married.

Now, to be clear, this isn't a free pass to forget your spouse's birthday (and no one should feel obligated to put up with someone being truly neglectful). The point here is that in the big scheme of things, any one single day is only a fleeting moment. If you're spending your life with someone you love, then every day is a gift.

10. Don't put other people out; don't let them down.

Whenever possible, avoid inconveniencing others (especially friends, family, and loved ones). If something you're doing must inconvenience anyone, it might as well be you and not them, right?

On the flip side...

11. It's OK to need help.

In this submission, Wendy tells us about some advice her dad gave her. "People need to be needed," he told her. If someone offers up help, don't hesitate to take them up on it.

12. Nothing worth doing comes easy.

Life is full of risk-taking opportunities. And while the word "risk" implies that something could go wrong or things could get worse, it also comes with the possibility that things could get much, much better. Now, of course, a great many risks aren't worth taking. Which ones you pursue is entirely up to you.

13. Relationship advice is a tricky tightrope.

Alyssa wrote about a relationship she was in once that had taken a toll on her personal and professional life. It was toxic, and others around her knew it. While this advice isn't for everyone (there are obviously some very real reasons why some people in toxic relationships don't or can't leave), for Alyssa, asking this question led down the path to happiness.

14. Think about the future.

This advice, shared by Kate, is an important truth about life and regret — regret both of what we do and what we don't do. In her work as a nursing assistant, Kate took care of elderly people. One woman gave her the simple advice to live life without regrets (which, hey, is pretty common advice, right?) but when she clarified it, it became way more profound.

15. Life's not fair.

Eugene shared a story about his growing up with a brother who had a tendency to take stuff out of his room without permission. After complaining about it, he came to realize that simply complaining didn't do anything. He had to accept and acknowledge the world for what it was (unfair) before he'd be able to change things for the better.

16. Revenge is a dish best served...

Melinda shares a classic bit of advice right up there with "kill 'em with kindness." Some people say, "Don't get mad, get even." Even better, though, is simply living well and letting those who've wronged you see what they've missed out on (and hopefully learn from their mistakes).

17. It doesn't get any more basic than this: Be kind.

Maybe this goes without saying, but being kind is one of the best things any person can do for themselves, for those around them, for friends, for strangers, for family, and for the world.

Be kind.