Have you ever had a job that was OK in all aspects, but nothing more? OK pay, OK hours, OK co-workers, OK tasks … what’s the problem? Maybe there was no problem and you still have that job, all these years later.

Did you feel that? That slight ground tremor came from millions of Americans shuddering simultaneously at the thought of a lifelong “OK” job. We’re a restless bunch and nothing aggravates that condition more than work without challenge.

Even so, it’s not easy to leave a job when there’s nothing wrong with it. We struggle to justify leaving, or we struggle with staying put. The inner conflict wears us down.

If you’re stuck in this in-between place, it might help to imagine an even more difficult scenario. Suppose your job was a dream job you had worked your whole life to attain. And suppose it landed you in the top tier of America’s earners. And now suppose that you’re tired of that job and want to walk away — even though you could keep it if you wanted to.

That’s essentially John Moffitt’s story. He’s the former Seattle Seahawks lineman who was traded to the Denver Broncos in August. That’s right – the Seahawks and Broncos who happen to be this year’s Super Bowl contenders. If Moffitt hadn’t left halfway through the season, that’s a Super Bowl he’d be playing in.

Ouch. Bad decision, right?

Not according to interviews Moffitt held at the time and later, even after it was clear which teams would vie for the championship. He has been consistent in saying that he’d grown tired of playing football. At 27, he’s ready for new challenges, and he was becoming disenchanted with the NFL ethos. He had also decided the physical risks weren’t outweighed by the substantial salary, or even a potential Super Bowl ring.

Following are five of the most common challenges I see when workers face their own employment crossroad.

1. Justifying the decision. Being bullied or underpaid would be a welcome relief to those who struggle to say out loud, “I just want something more.” It’s even worse when you can’t articulate what “more” would be. Without a goal in mind, it can sound like whining to say you want out. And few people would consider leaving a job without another one lined up.

2. Having no urgency. Again, with no compelling problem with your job, it’s hard to create a false deadline for leaving. And without a deadline, it’s difficult to make a strategy.

3. Overcoming inertia. The cousin of having no urgency, inertia wreaks a special kind of havoc on a budding flight plan. Inertia almost assures that no steps are taken, or that the steps taken will fail for lack of effort. These small failures tend to look huge in retrospect, making you feel that any future attempts will be similarly doomed. It’s a bad cycle that’s hard to break.

4. Finding the time. After all, unsatisfying or not, you’re still busy working. With time as a barrier, it’s easy to slip back into inertia and let the whole thing go.

5. Managing the guilt. Perhaps leaving your job “just because” feels like a betrayal to your boss or your family. Or perhaps your guilt comes from leaving a perfectly good job when others are desperately unemployed. Whatever the source, guilt could be the final nail in the coffin for this particular decision.

Did that list contain any of the challenges that you’ve encountered? Here’s the thing about leaving an OK job: You’ll never be sure it’s the right thing to do until after you do it. Sometimes not until years after you do it. So you can’t try to think your way into this decision. You just have to take the precautions needed to protect your finances and professional reputation. Then you have to make the move, even if it means walking into the unknown.

Or, to put it another way, you could follow Moffitt’s exit strategy as he described it to Los Angeles Times reporter Sam Farmer this week: “The way I look at it is, I did that dream … I’m going to create a new dream.”

(You can follow Moffitt on Twitter at @moffitt74. Here he calls himself “A former Seahawk and Bronco. Now, active happiness pursuer.”)