Not too long ago, here on I trawled through the wisdom of Q-and-A site Quora for life regrets to warn readers about. Specifically, I was on the lookout not for the type of grandiose screwups that everyone knows people often regret, but the quieter coulda-woulda-shoulda's that haunt folks' senior years, so that you could avoid these errors.

But it's not just those rocking a head of gray hair who can have too much of their time consumed by regret. Elsewhere on Quora a curious user asks, "Do you regret any major life decisions you made in your 20s?" (Hat tip to Business Insider for pointing out the thread.) The answer, according to an outpouring of responses, appears to be, sure.

Apparently, people waste no time in making missteps they'll regret for years to come. Here are some of the most popular responses to help make sure you don't get introduced to major regret before you enter your fourth decade.

1. Letting the party go on a little too long

Sure, your 20s is usually a life period where you're pretty free of responsibilities, and many of us use that time to enjoy life and go a little wild. But take this too far and you will regret it, warn a number of Quora users. "I wasted a lot of time experimenting with alcohol and various drugs--this experiment lasted for a good five years," laments trainer Carl Logan.

Entrepreneur Amar Patel, for his part, doesn't entirely regret his experiments with mind-altering substances, "yet, at after a certain point, it became a hindrance and was leading to a lower quality of life," he admits.

2. Living the life your parents want for you, not the one you want

One of the top regrets of seniors is following others' expectations for their life rather than their own dreams and preferences. Apparently, there's a particular flavor of this problem that's common as early as your 20s--living out your parents' aspirations, not your own.

Life coach Riina Rinkineva, for instance, reports that one of her top regrets from her 20s is "not standing my ground against my parents for what I wanted for myself in my life and what I didn't want."

3. Working on a relationship before you work on yourself

According to both everyday wisdom and reams of research, love is central to happiness. But you can't really form a quality relationship with someone else until you have your own self sorted, caution several Quora respondents. Rush things and you'll just end up in a regrettable muddle.

Artist Diane O'Neill, for example, says she regrets her early marriage. "I should have first found out who I was and what I was capable of achieving as an individual; I became someone's wife long before I found out what I wanted to do personally," she explains.

4. Confusing a job and a career

Your 20s are almost always a decade of professional growth. Several respondents cautioned that you can slow that process if you're not clear with yourself about the value of any particular gig. For some folks that means investing too much in a rent-paying gig they aren't passionate about. For others it means failing to see to see that their current job or interest could and should be built into a real career.

Logan, for instance, put too much energy into traveling the wrong path. "I wasted a lot of time in what I thought was a career--the broadcasting industry is a career for some, but for me, it was just a job," he writes. On the opposite end of the scale, Patel frittered away his time in "dead-end jobs in cafés, as a salesman, as a technician" when he should have been building a career.

You can regret either under- or overinvesting in your work, the lesson seems to be. What you won't regret is being clear-eyed about your longer-term professional trajectory and whether today's effort is serving your goals, whatever they may be.

5. Not exercising

Your body is at its peak when you're young. Keep it healthy, or you'll soon regret it. "I never worked out. If I had hit the gym, I probably would've been a lot happier and would've had more success with the opposite sex," writes Logan. Among the regrets of respondent Yash Mishra was something similar: "Paying for the gym and then [being] too lazy to get up."

Bonus tip: Letting fear of regret hold you back

As an end note, it's also worth pointing out that while plenty of Quora members had regrets from their 20s to share, many others stressed that being too concerned about not making mistakes can paralyze you, keeping you from necessary experimentation and learning in your youth. Don't let fear of regret keep you from trying and failing constructively, this group stresses.

"I know that [the things I regret] made my life more difficult at the time, but they are a part of who I am today, and I think I am a better person because of those experiences. I think everyone has to go through a period of stupidity to really appreciate finally being an adult," writes teacher Elizabeth Knight in one such reply.

It's a healthy dose of perspective--keep these regrets in mind to try to avoid them, but don't be held back by your fear of screwing up. Inevitably you will. Most of the time not only will you survive your misstep, but you'll also come out a better person.

What's your top regret from your 20s?