I'll never forget pressing the "send" button on the e-mail to my boss letting him know that I was leaving to start a company. It was a terrifying and thrilling moment best summed up by my father when I told him the news: "Well, you just jumped of a cliff, now you just have to build your wings before you hit the ground."

The weeks leading up to the big moment were equally as exhilarating. I had trouble sleeping and my apartment walls were covered with master plans and a six-foot high, 20-foot long timeline laying out the first six months of Napkin Labs. It was all I thought about.

Leading up to that pivotal moment was a ton of research, long conversations with family and friends, potential customers, and reading a million blogs. Unfortunately, there was no magical list, formula, or star formation that would give me the answer. I eventually realized that I would never know for sure; I couldn’t rationalize my way there.

So, what drove me to take the leap?

I believe it was the accumulation of inspiring moments, pieces of advice, and finding great co-founders, each building up a sense of urgency and excitement that one day became too strong to ignore.

While motivation can literally stem from anywhere, a big part of the process, for me, was talking to people who had already made the leap themselves. So, in an attempt to help aspiring entrepreneurs who are thinking about starting a company, I've compiled a list of signs you might be ready from entrepreneurs who have done it.

"If you search the Internet every morning to make sure someone hasn't launched a business like the one you were envisioning...you might be ready to start the company."
—Alex White, co-founder and CEO of Next Big Sound

"You know you're ready to start a company when you are more attracted to building something people truly love than you value your sanity, stability, or life as you know it."
—Ari Newman, founder of Filtr Box, which has been acquired by Jive

"If you can pick just two areas in your life to do well—family, friendships, fitness, diet, rest, sanity, and entrepreneurism—and entrepreneurism is one of them, then you're ready to start a company."
—Neil Robertson, Founder, CEO of Trada

—Jake Nickell, founder and mission commander, Threadless

"You know you're ready to start a company if you recognize you have something no one else does: your own career path and ideas that have informed your decisions and brought you to this place."
—Prasad Thammineni, CEO of OfficeDrop

"You know you're ready to start a company when it's the only career move that will make you happy. Starting my own company gave me the chance to create an organization and a culture that reflected my own values. With that mindset, you can't lose, because regardless of outcome, the company you build is the truest expression of who you are."
—Hamilton Chan, CEO and founder of Paperlinks

"Is your business idea something you think about while in the shower? If you've had moments where you've hopped out of the shower and run to scribble some notes down while wet and naked, then you might be ready to start a company."
—Hansoo Lee and Bhavin Parikh, founders of Magoosh

"If you are ready to beg and plead for ideas to improve your service from anyone and everyone—you might be ready to start a company."
—Jeremy Bloom, founder of Integrate.com

You'll never be able to rationally conclude that you’re ready to throw away all the material certainties in your life and begin your quest to start a company. Sometimes you just have to wait for a source of inspiration that convinces you there’s nothing else in the world you should be doing than pursuing the idea you’ve been thinking about for months, or even years. I hope that one of the comments above will drive you one step closer to having the courage to do so.