Four years ago, I took a career about-face, leaving my job as a psychotherapist to join the world of startups at a venture capital incubator. I gave up one kind of emotional grind for another. It's one thing to see patients for 50 minutes once a week, it's an entirely separate thing to live and breathe the crazy ins and outs of the startup life with hundreds of people hustling to make their companies succeed.

It has been the wildest, messiest, most intense four years of my life. Through yelling matches, hard conversations, battles of love and wits and ego, and lots of shared laughter, I've learned a tremendous amount about myself. Here are a couple of the more salient lessons.

1. Your purpose in life has very little to do with your job.

In the past four years, I've been a psychotherapist, teacher, mentor, investor, and entrepreneur. It's so tempting to say with certitude that this job or that job is my purpose. That I'm "called" to be a counselor, a teacher, or a CEO.

But rather than using my roles as labels to define and decode my purpose, I now think of them as reflections of who I am now, in this moment in time, with these people I work and share my life with. And perhaps more important, these jobs are helping me become who I am supposed to be.

Your purpose is to unlock--and eventually fold in--who you are becoming with who you already are. The activities that force you to grow are your calling. Learning from those activities is your purpose.

Your life purpose is way too big to be filled by one role, or even one long career. If you choose wisely, your job can point you toward your purpose.

Your personal evolution--becoming wiser, kinder, more curious, more you--is the purpose of your human experience.

Your job, if you're lucky, might serve as the flint that sparks your growth, or, as some of you know too well, it may take the form of a psychic straightjacket and be inflexible and unaccommodating. Either way, your job is a reflection of your current conditions--not the purpose itself.

2. Discovering who you aren't is a worthy use of time.

Author Anne Lamott says, "You have to make mistakes to find out who you aren't. You take the action, and the insight follows: You don't think your way into becoming yourself."

Taking a cue from Lamott, once a week I write down one thing that I no longer agree with. These are usually rules from childhood about what it means to be a woman, a good mom, and a successful person.

And then I break it. I try on what it's like to do something different, as if I'd never known the original rule. This has lead to insights about who I really am, and who I no longer care to be.

For example, I am deeply empathic, but what I'm no longer OK with is being an emotional martyr. Someone else's needs are not more important than my own. I can be kind and ferociously ambitious at the same time. I can be tuned in to people's emotions, but decide when I've had enough or when caring about them too deeply is holding me back.

Discarding the leftover oughts and shoulds from my early years has cleared up psychic space to write some new rules.

I think this is what Joseph Campbell meant when he said, "We must be willing to let go of the life we have planned so as to have the life that is waiting for us." We have to be courageous enough to let go of what no longer serves us in order to step into something new, and probably a lot bigger.

I'd like to think that I would have eventually learned these lessons even without my career change, but there's something about wading through the anxiety of the unknown that gives you an opportunity to pay closer attention. Even when it stings, jumping into the deep end with eyes wide open can reveal something beautiful.