The trouble with wisdom is that, by definition, it takes a while to develop. And unfortunately, by the time you know a thing or two about how to live, you've already often made more than a few serious errors.

Most of these missteps can be corrected, but some are harder to recover from than others. Your best bet, then, is borrow other people's wisdom -- while you can't always rely on your own experience, someone else almost certainly has faced the same dilemmas and trade offs you are struggling with and can tell you more about the dangers and workarounds.

Where can you find this wisdom? A huge and helpful thread on question-and-answer site Quora in response to the question "What are the lessons people most often learn too late in life?" is an incredible free source of other people's mistakes and learnings. I culled several of the more useful and frequently repeated life lessons from the answers:

1. Hustle is the antidote to fear.

This one comes from blogger and entrepreneur Nelson Wang. Before starting his website, he reports, he was full of fear: "What if I wrote for years and no one ended up going to my website? What if no one really cared about motivation?" But instead of waiting to overcome his fear to get started, he got started in order to overcome his fear. The fact that this works is a lesson many people learn too late, if at all, he feels.

Wang suggests that, to avoid this slip up, you heed these words from Richard Branson: "If somebody offers you an amazing opportunity but you are not sure you can do it, say yes -- then learn how to do it later!"

2. Nothing is as important as health (and you don't have to sacrifice your health to be successful).

Lots of respondents offered answers of this type, but the specific formulation used in the first half of this heading comes from lawyer Pradeeta Mishra. "It is a horrible truth that comes to us only when we fall terribly sick -- of our own accord or otherwise," she writes.

Wang agrees, stressing that any bargain that asks you to sacrifice your physical well-being isn't worth it. Meanwhile, self-described "product guy" Christian Bonilla dedicates much of his answer to convincing readers that you don't have to work yourself into illness or an early grave to be successful.

"I think the majority of the pain from overwork is self-inflicted. In big companies where you have lots of people at the junior levels, you'll see hordes of young people who try to outwork each other in a competition to see who can work the most nights and weekends and produce the most output the fastest. Many companies implicitly or even explicitly encourage this," he says, "but it's often an inefficient way to reach your goals. Working on the right things is more important than simply working a lot."

3. None of the best experiences of your life will happen staring at a screen.

"If you want more of the best experiences of your life, minimize the time you spend in front of [a computer screen, a phone screen, or a TV]," says CEO Evan Asano. I don't think this one demands too much more explanation.

4. Happiness is a habit, not an aspiration.

The exact expression above also comes from Asano, but lots of respondents made similar points.

Wang puts it this way: "Happiness is a state of mind, not a destination.... Looking back on my life, the unhappiest moments of my life occurred when I always thought I had to achieve a certain goal to be happy. That's not the way happiness works. You can be happy right now. Be happy that you're alive. You're breathing. You're here in this incredible moment that we call life." (Science backs him up.)

5. Be careful what you get good at.

More excellent career wisdom from Bonilla: "The great paradox of learning is that diverse expertise gives you freedom to try more new things, but gaining expertise in one area always means ignoring others, reducing your freedom. Developing expertise in anything worthwhile takes time, and your time is limited.... If you don't pay attention to where you accumulate skills, you can make important career decisions completely by accident. We do the things for a living that we know how to do well. You are what you learn."

"It's easy to get stuck in a field simply because that's what you know, whether or not you find it fulfilling," he warns. (This is very true in my personal experience. How about you?) With this is mind, he offers young people this advice: "You'll be much happier if you choose your career path consciously rather than allow time to make decisions for you."

What life lessons would you add to this list?