Editor's note: We asked noted entrepreneurs to reflect on what they wish they'd known starting out and to put it in a letter to their younger selves. Carter and Courtney Reum are two brothers who started two companies and whose VeeV Acai Spirit ranked No. 242 on the Inc. 5000 list of fastest-growing private companies in the U.S. in 2011.

Dear Carter and Courtney,

As operators and entrepreneurs, you're both always looking for ways to improve, whether that means scaling faster, growing more strategically, or becoming more self aware.

So, what should you know? What, in hindsight, should be the most impactful thing you should focus on earlier in your careers?

Focus on Cultivating Self Awareness as early as possible.

Billie Jean King called it the most important trait to becoming a champion. Now, with some hindsight (and self-awareness), you'll soon see how cultivating this -- knowledge of yourselves -- is absolutely critical to being successful.

The essence of self-awareness is understanding yourselves -- what motivates you, what are your proclivities, what are your shortcomings? When do you make your best decisions and how do you handle your "down" moments? What scares you? What are your positive habits and which ones are no longer serving you?

As you'll learn, these are not questions you can sit down and answer in one session. These questions take a long time to answer as you slowly peel back the layers, getting closer and closer to the core, and this is why we you'll wish you started focusing on this even earlier in your careers.

One of the biggest benefits of learning more about yourselves is you're surrounded with people who complement you. Self-awareness is critical in building teams for this reason. You're also able to stop pushing against yourself and instead focus on the areas where you're strong and not those areas that drain you.

You'll be doing this with M13 and wish you had done it more with VEEV. With VEEV, like many first time CEOs, you'll think the founders should be able to do everything: marketing, sales, HR, operations, and so forth. All of these functions are required in any business, and often business owners develop or try to develop the skills required to answer the needs arising in the business. And while being able to grow and learn are crucial founder-traits, it's impossible or, at the very least, inefficient to try to become skilled in everything.

The opposite approach is letting your strengths dictate your business. This strategy will never be completely achievable and that is not the intent: it's a different paradigm for thinking about your growth and your business. In order to be successful with VEEV, you'll have to gain distribution, market your brand and products very well, and ultimately gain consumer traction and move product off shelves. None of these activities are ones you both are best-in-class at, but you'll have to do them to pull-through.

Now, with M13, and what you'll wish you started to do earlier, is to let your strengths, passions, and natural inclinations dictate your activity set as opposed to doing the reverse. This requires deep awareness of what those internal drivers are and how to tap into them. You both love to connect the dots: bring the pieces of the puzzle (including the right people, strategies, tools, and partner companies) together to scale brands. Your energies now go to the coordination of the pieces, rather than the individual pieces like you once were doing with VEEV.

You'll realize how incredibly lucky you are and, like most, you can't always do things that give you energy early on in your career. It's a luxury that's usually earned, not given, and you believe good things come to those who wait and work hard. Keep grinding and cultivating a deep understanding of yourselves. Over time, this will allow you both to understand what you want and what you need to successfully dictate the work on your plate.