We all get advice from time to time from the people we know: Colleagues, friends, relatives. (Even our children like to weigh in on what we should or shouldn't do.)

But how do we know when we've found a mentor?

Mentors are those special individuals who care about you enough to share their wisdom and guide you along your personal and professional journey.

A mentor's words carry more weight--and have an even more far-reaching impact on your life --than the stream of advice (some of it useful, some not) that you're subject to receiving each day.

Here are 7 signs that can tell you if you've found a true mentor:

1. Mentors are problem-solving partners.

Mentors are great at providing a sounding board for those knotty issues you can't seem to figure out yourself. They can ask the questions you need to ask that will help you break down a complex issue and get to the root of a problem so you can, hopefully, solve it.

Interestingly, the root of the word "mentor" -- "men" --means "to think." A mentor, therefore, is also a thinker --a highly relevant attribute for someone that is tasked with helping you to solve difficult problems.

2. Mentors give you directions -- but it's up to you to find your own way.

Mentors can be tremendously helpful in helping lay out possible options you can pursue, or the directions you might take in your career, or in life. But ultimately, the decisions are entirely up to you, and the responsibility for the consequences of those decisions lies in your hands.

The two career mentors I've known over the past decade have given me tools for thinking through and planning where I want to take my career both in the near-term and beyond. They've shared their decades of experience and wisdom, and inspired ideas and helped me set goals that I probably wouldn't have even thought of without their help.

And yet, at the end of the day, I am the one responsible for acting on their advice -- or not.

3. Mentors challenge you.

My best mentors have been the ones who have challenged me. They've pushed me to question my assumptions about my abilities and potential; urged me to set my sights on higher goals; and held me accountable for reaching them.

4. Mentors tell you the truth.

Often, the greatest gift a mentor can bestow upon you is the truth--even if it stings a little (or a lot). By telling the unvarnished truth, mentors can help you break out of self-limiting beliefs that might be hindering you from making progress toward your goals.

5. Mentors give you courage to take action.

A few thousand miles to the east of ancient Greece, the Chinese philosopher Laozi said, "a journey of a thousand miles begins with a single step." Mentors are often the ones who give you the courage to take that first step   into the unknown.

6. You don't always have to agree with your mentor --nor heed their advice.

While I've listened to much wise and well-intentioned advice, the fact that I haven't always followed the (very reasonable and well-intentioned) advice given to me is a lesson in itself: That sometimes, you just need to pursue what you feel is right for you, regardless of what the "voices of reason" might tell you at the time.

7. You don't even have to know your mentor very well (or at all).

Some people whom I would consider mentors I've known only a very short time --or not at all. I consider the late author and writing teacher William Zinsser to be one of my most instrumental writing mentors-- even though I never had the chance to meet him.