Looking for Unconventional Inspirational Quotes? Consider Your Rejections. Hundreds of investors turned me down, so I put their rejections on a wall for everyone to see. It quickly became our call to succeed.

I was co-CIO of MetLife when I got tired of waiting for solutions to the problems I knew were holding enterprises back. So in 2017, after 25 years in corporate, I left to build the solution myself.

I founded Unqork, a platform that helps large enterprises create complex, custom software without writing a single line of code. "We will become the only technology every company is using" — that was the pitch. Then I set out for both coasts to raise a lot of money.

I pitched 300 investors. And 300 investors said no.

Related: Rejection Is Part of Entrepreneurship. Here's How to Handle It.

That was interesting. So I put their feedback up on a wall in our office, and it became a rallying cry for my team. We call it "the Wall of Inspiration" — and in just three years, we are at 370 employees and have raised more than $360 million at a $2 billion valuation (none, by the way, from those initial 300 investors). Here are four of my favorite rejections, and how I took them.

1. "You're too old."

Then the investor continued:"At your age, you should already have three successful exits by now." I'm 45, I thought, and I've spent two decades in Fortune 500 technology leadership. Call that too old, if you want, but what I'm doing requires someone with deep knowledge of corporate America in order to solve its problems.

2. "Team appeared a little naive as to what it takes to sell enterprise software."

True: No one I'd hired sold enterprise software. But my exec team, including partners at McKinsey and KPMG, worked for firms much like our clients. This comment clarified our position. Most enterprise salespeople try to convince execs: "Buy 10,000 licenses now and I'll give you a great price!" Then the client uses 10 percent of what it bought. By contrast, our clients pay only for what they use. That required a team with deep industry experience.

Related: How to Gracefully Handle and Then Make the Most of Professional Rejection

3. "Focus on only one client. Focus only on insurance."

I disagree. I actually wanted to make sure that our platform wasn't dependent on one client, or locked into a single industry. Today our strength is exactly that — our clients are across industries, which provides us stability even in pandemic times.

4. "Don't present in any conferences; be off the radar."

Microsoft asked me to speak at a big conference, and I agreed. "Oh, no, no; you have to be in stealth mode!" an investor chided. He thought a bigger player would see me speak and rip off my idea. But my goal was to get out there and get as many clients as I could, setting us up for actual revenue before funding.