Should you stay, or should you go?

Almost every aspiring entrepreneur wrestles with this question at some point in  his or her career. You have a perfectly decent job on paper, but you just can't kick that nagging urge to throw it all in and do something radically different. When should you soldier on, and when should you listen to your gut?

There are usually compelling arguments to consider on both sides of the argument in such cases. Many people's professional dissatisfaction is at least partially down to attitude, and a change of viewpoint can have radical effects on how much you enjoy your work. On the other hand, the best time to get out of a truly ill-fitting career is yesterday. But there is one sure sign that you should start looking for the exit--when your career stops challenging you.

One of the surest ways to get smarter is to surround yourself with those who are more intelligent than you and to insist on regularly stretching yourself beyond your comfort zone. If you're just too smart for your current gig, that's just not going to happen, insisted Liz Ryan, founder and CEO of Human Workplace on LinkedIn recently.

"When you have a lot to bring to a job, you want your muscles exercised. You want your brain to be busy. You want to solve hard problems yourself and with other smart people. Parrots and rabbits need something hard to chew on, and so do we," she writes. So how do you know if you're just restless or whether it's really time to look for a more demanding gig? Ryan offers several suggestions, including:

1. Problem, what problem?

Doing the same thing over and over again in the exact same way never taught anyone anything. If your co-workers are interested only in repeatedly treading the same well worn paths, then it's unlikely you'll start expanding your skills anytime soon, according to Ryan. "Your co-workers may be the nicest people on earth, but if they don't understand what you're talking about when you lay out frame-shifting ideas or if they can't hold a conversation about anything except the way they've always done things, you're in the wrong place," she writes.

2. No one is mentor material.

It bears repeating: Hanging out with smart folks makes you smarter. If you look around and don't see anyone you really want to learn from at your current place of employment, that's a huge red flag. Ask yourself: "Whom do I spar with? Who stimulates me mentally at work? Whom do I look up to and learn from?" If the answer is, "No one," it's time to start plotting your escape, Ryan suggests.

3. No vision at the top.

It's hard to progress if you have no idea what you're working toward, and, unless you're very far advanced in your career, that vision for your team, department, or company should come from the top. If instead you're getting radio silence about where the organization is headed, then the scope for meaningful contribution is severely limited. "You can't grow your flame working for someone who has no idea what a vision is or where to get one. You have to learn from your boss," warns Ryan.