The more I fail -- and the more I succeed -- the more my definition of success evolves. In the past eighteen months, I've had plenty of failures: the SuperPAC I launched to try to find a better Mayor for New York City fell flat, the tv pilot I wrote has completely stalled, and one of the subsidiaries of our holding company is effectively defunct.

We've also enjoyed some success: we raised a traditional venture capital fund, we pioneered a new equity for services approach to venture capital, our foundation passed legislation expanding school breakfast in Pennsylvania and is getting mobile voting off the ground, and we launched a column and a podcast and signed a book deal.

But the constant ebb and flow has helped me realize that my initial evaluation of what success requires was probably wrong. Here's what I've learned:

Talent + Resilience = Success.

People tend to overrate talent. It's necessary -- for example, no matter how much I practice, I'm never going to have the talent to play point guard for the Knicks (well, given how bad the Knicks are, maybe that's a bad example). Without a baseline amount of intelligence, instincts, creativity and mental agility, it's tough to get anything done. But those are just table stakes. The second half of the equation is much more important. Hard work, risk tolerance, street smarts, discipline, perseverance, and some more hard work is the real arbiter between success and failure. As an employer, I want people who haven't had everything handed to them (we even now have a "no hiring millennials out of Ivy League schools" policy). I want people who keep pushing and pushing forward but are also self aware enough to recognize when their approach isn't working and try something entirely new. A few extra IQ points rarely makes a material difference. Perseverance does.

Keep shooting.

I fail a lot. And we succeed a lot too. Sometimes there's a good reason why something fails (you didn't work hard enough, it wasn't a big enough priority, you weren't willing to sacrifice for it). Sometimes the stars just don't align. But ultimately, the more you throw against the wall, the more sticks. We've got four companies, an investment fund, a family foundation, two weekly columns, a podcast and a book. At any given moment, half a dozen things aren't going well. But because we do so many different things, at any given moment, half a dozen things are also going right. Diversified volume mitigates failure.

The definition of success is extremely variable.

There are 7.5 billion people on the earth and 7.5 billion different combinations of DNA. Everyone's different. And when your definition of success is based on someone else's opinion, you're highly unlikely to ever actually succeed. The only definition that matters is your own. For much of the last few years, I found myself measuring my success and self-worth based on how much money, power and influence I could accumulate. I was pretty miserable. When I finally realized that success, for me, was a constant mix of intellectual work, philanthropic work, producing creative content, some sparring and challenging the status quo, some basic commercialism and enough free time to focus not only on my family but my friends and even totally unproductive hobbies, I felt happy. And that made me feel successful. Society has a lot of arbitrary metrics to define success. Chasing them is a losing battle.

But perhaps the most important lesson of all is that success changes -- in definition and in reality -- as you change. At 44, my perspective is very is different from when I was 22. I suspect it'll be really different again by time I'm 66. If it didn't evolve, I'd probably live on the top floor of Trump Tower and eat wings every night.

Success is variable. And how you define it impacts your happiness exponentially. So perhaps the best definition of success isn't an equation like talent plus resilience but just knowing in your gut if what you're doing makes you feel fulfilled and happy.

If it does, no one can argue you're not a success. And if it doesn't, all the external signals in the world don't really mean much.

Hopefully it won't take all of you as long as it took me to realize that.