How to Know When It's Time to Walk Away Starting a business takes passion -- and often a reality check. Here's how to know when moving on might be the best thing for your business.

"You know the saying: If you can't be a good example, at least serve as a warning to others. Consider this exhibit A for knowing when to walk away.

My friend's grandfather had dreamt of starting his own company for literally half a century. Ideas that were creative and ahead of their time when he conceived them are now sadly and severely out of date. He's lost his wife, his home, his career and his financial security to this dream. Yet he still won't let it go.

Over the years, he's changed his pitch, his approach and his list of potential contacts, but he still hasn't raised a dime or sold much of anything. Now in his 70s, he's still pitching his tired ideas to whoever will listen, all while spending his minimal disposable income on postage and copying costs.

I know what you're thinking: This can't ever happen to me. Right? You've poured your heart and soul, your time, your money and more into your business, so it simply must succeed. While that's nice to say, it's not always true. The more you're able to realize that success can come and go, the better positioned you'll be to take advantage of other, more promising opportunities.

Here's how to know when to say when:

• Are you the only one who still believes in your business? Sometimes the smartest people can have a blind spot when it comes to their own vision. Like that girl or boyfriend that all of your family and friends didn't like -- it may be time to get a clue.

• Related: 8 Tips for Finding Foucs and Nixing Distractions

• Are the competitors actually better? One idea my friend's grandfather had for a business consisted of wrapping a belt around a person's waist to allow him to swim laps in a small pool. Well, there's now a small pool with a natural current you can set to whatever speed you want to swim forward without actually moving. Most people would choose that over wearing a belt in the water, but he still thinks his idea is better. He's wrong.

• How often have you landed a second meeting? If your days are spent contacting new people to invest or buy but you never get past that initial meeting, chances are you're not offering something worth a second look. Yes, we've all heard those stories about the concept of copying being rejected by Polaroid, and the initial dismissal of Post-its, but those stories are rare. If you've been going to first meeting after first meeting with no success, either change or quit.

• Related: How to Craft a Business Plan That'll Turn Investors' Heads

• Are you hitting a wall? You've heard the definition of insanity: Doing the same thing over and over and expecting different results. If you've run out of approaches, ideas or directions, maybe the basic concept is just unworkable.

We have a tendency to admire persistence and belittle a quitter. Don't think that way. Ask yourself, "Is this the last good idea I'm ever going to have?" Sometimes success is about letting go of your current dream so that you have room for others.