Quitting your job is one of the most liberating yet scariest decisions you can ever make in your career. Through quitting my corporate jobs, writing my book, Fire Me I Beg You, and having countless in-person and virtual coffee meetings, I've noticed countless signs that shouldn't be ignored.

However, there is one sign that trumps the rest.

Imagine you're at your weekly status meeting and everyone is sharing their updates. Then your manager starts giving feedback on everyone's status and goes off on a rant about something else. As he's talking, you can't help the sinking feeling in your stomach. It's been brewing for a long time, but you never really knew what it was.

Then it dawned on you: You don't think your manager is doing a great job leading. In fact, you think you're smarter than your boss and you could be doing a better job than him.

That is the No. 1 sign that it is time for you to walk away and live out your bigger purpose. Now you can start planning your next move and begin growing, learning, and feeling challenged again. Here are some recommendations:

Start looking for another job, but don't tell anyone.

People make two mistakes when they're miserable with their jobs:

1. They don't do anything at all.

2. They become a "Negative Nancy" and make sure everyone knows they are miserable.

So the first thing you should do is be positive and most importantly, shut your mouth. Don't quit just yet. Also don't tell anyone at work you're thinking of quitting. Take your time to carefully research and plan for your next adventure, away from the office, on your own time.

Have coffee meetings.

When I quit my consulting job at Deloitte, I knew I wanted to jump from the corporate world to the startup world, but I wasn't sure what exactly that would entail. So I did what any truly lost entrepreneur would do and began having lots and lots of coffee meetings.

Coffee meetings are a great way to strengthen your professional network and uncover hidden opportunities. You can use tools like LinkedIn to research and connect with people you might enjoy meeting over coffee. Remember to make it worth their time by adding value to them too.

Start a side hustle.

Almost everyone has a side hustle these days. Side hustling while working in a full-time role is a fun way to align your passion with income, or at least try to blend the two.

If it doesn't work, you won't live with regret since you would have tried and learned something new. If it does work, you might never have to work in a miserable job again.

Find someone smarter than you.

Reading books and watching inspirational videos about smart people is one thing, but actually surrounding yourself with people smarter than you can help you learn and grow tremendously. Even people you're smarter than, like your boss for example, can give you a few pointers on what not to do.

Outside of your workplace, you want to seek out mentors and coaches who have done what you want to do. Mentoring relationships are formed organically, but coaching is usually paid and more structured. Hiring a coach can help you gain clarity and answer specific questions related to job search, resumes, interviews, salary negotiation, side hustling, and more. Before you jump in, remember to do your research and be sure their areas of expertise and results fit your needs. Tools like LinkedIn make it easy to connect and maintain relationships with smart people even when you aren't necessarily looking for a new job.

Stay positive.

Deep down, we know staying positive and practicing self-care is good for us, yet, when we get busy or stressed out, it is the last thing on our mind. As a result, our overall quality of life goes down.

Sipping coffee and writing help me analyze my thoughts better. For you, it might be reading, running, cooking, gardening, or any activity you've always wanted to try but never had the time for. Try to incorporate a few quick activities into your morning and evening routines, and plan on at least one longer activity each week. Your future self will thank you.

It might not make sense for you to quit your job right this minute, but if you see the number one sign, you know it's time to start planning your exit. I hope you find these suggestions helpful, and that you won't have to stay miserable for long.

Published on: Feb 26, 2019
The opinions expressed here by Inc.com columnists are their own, not those of Inc.com.