Jason Lange is the CEO and co-founder of BloomBoard, a company dedicated to bettering the K-12 education space by providing a marketplace for personalizing educator development.

As an entrepreneur, you end up having a lot of advice thrown your way--especially when you're starting out. Everybody from your first mentor to your uncle seems to have an opinion on what you should and shouldn't do.

You take some of the suggestions, and quietly ignore others. There's always advice you later wish you'd considered, but sometimes, ignoring conventional wisdom is necessary for real growth.

Of all the advice I've received, three pieces have shaped my approach to business and my attitude toward life. Whether you decide to take these lessons to heart or ignore them is up to you, but they've helped me get more out of every experience.

1. Remember the rule of thirds.

No matter what you do in life, a third of the people you come in contact with will love you, a third will dislike you, and the rest will be indifferent.

The rule of thirds is obviously an approximation, but it serves as a good reminder that you shouldn't waste time trying to make everyone your fan. Every moment you spend trying to win over someone you can never please will just distract you from the people who actually like you and believe in what you do.

When I started applying the rule of thirds to my business, I stopped caring whether my peers thought what I was doing was "right" and fixated on what seemed right to me. Instead of trying to bring other professionals and customers around to my way of thinking, I had more opportunities to engage with like-minded individuals who were excited about my business.

By learning how to quickly assess which category people fall into, you can focus your energy on the people who love you, which makes life much easier to navigate.

2. Bad things happen, even to really good people.

Every experienced entrepreneur knows all too well that bad things happen to even the best ideas and people. There are far too many lows to dwell on, and you'll waste an incredible amount of time if you give them more credence than the highs. The sooner you accept that life isn't fair, the sooner you'll stop wasting your time worrying and regretting and start working to make an impact.

Learn to get comfortable with the uncomfortable. Your strength as a leader will often hinge on your ability to have the tough conversations with your team and customers. Nobody wants to get fired or hear your business lost its biggest client, but how we behave in these situations often defines us as leaders.

Remember: The world is not a meritocracy. Stop whining about the bumps, and keep charging down the road.

3. Be present at home and at work.

Everything moves fast these days: work, school, home life, and relationships. Each of us wakes up, one day after another, only to be amazed that so much time has passed and a new phase of life has begun. Staying present in the moment is the only thing you can do to avoid missing out on life.

This will help you in countless ways--from being 100 percent "there" when your customer needs you to maintaining a healthy life-work balance. Given all the stress of a startup, I'm sure my wife would have left long ago if I hadn't been able to walk through the door and leave work at work (and if I didn't give excellent back rubs).

Focus on people, not problems. Listen to your customers, employees, and spouse. When you learn how to truly cherish each moment and the people you're with, you'll worry less, laugh more, and take a break from whatever dilemma you might be facing.

Each of these pieces of advice is easier to give than take. But if you learn to rewire your thinking to focus on the now and quit worrying about negative events or people, you'll not only enjoy a dramatic improvement in your business--but you'll also begin to appreciate the little wins in day-to-day life.