Last weekend, I attended my 10-year Stanford University reunion.

My college years were some of the most important and formative of my life. I arrived on campus in 2009 as an 18-year-old with the arrogance of someone who had yet to take a real punch to the face. I graduated in 2013 as a 22-year-old with the humility of someone who had recovered from a whole lot of bruises.

The reunion was a great time to look back on those years, reconnect with old friends, and reflect on some of the lessons of the first 10 years in the real world.

Here are 10 lessons I learned at my 10-year reunion.

#1: The Medici Effect is real.

In the 15th century, the Medici family began funding the arts, which led to many of the great artists and thinkers of the generation converging on Florence at a single point in time.

The concentration of talent in one location led to an explosion of innovation that gave rise to the entire Renaissance movement.

College campuses are like mini versions of 15th century Florence, with a high density of interesting people leading to new ideas and insights.

It struck me that many people had left campus in 2013 and never experienced anything like it ever again.

Conversely, those who had made an effort to live in or frequent high density locations had experienced the benefits they provide.

I always feel new energy after spending time with big thinkers in a single physical location. My advice: Find those places and spend more time in them.

#2: Your daily habits show up on your face after 10 years.

When you're young, you can get away with treating your body and mind like crap. You can eat and drink too much, sleep too little, and exercise too infrequently.

But you can't hide forever.

10 years later, your good (or bad) daily habits show up on your face.

Remember this and act accordingly.

#3: Insecurity tells, confidence shows.

People who are crushing it rarely feel a need to tell you that they’re crushing it.

As a rule of thumb, if someone immediately brags about their wealth or success, it's fair to assume the reality is likely a fraction of what they claim.

The people who have really crushed it were the first to ask questions and listen, not talk about themselves.

Insecurity is loud, confidence is quiet.

#4: Plans are great, but life will generally laugh at them.

We all graduated with five and ten-year plans for our lives. A bunch of ambitious young people who know exactly how life is going to play out in front of us.

But there's an old saying: Man Plans, and God Laughs.

Most of those plans fell apart along the way.

Those who are thriving had kept their compass pointed in the general direction of their dreams, but more importantly, they had learned to take the blows and pivot on the fly.

It's ok if life (or God, if you believe in that) laughs at your plans. Laugh right along with it and keep moving forward.

#5: Fighting the Zebra Effect is hard (but worth it).

Researchers struggled to study zebras in the wild because the black and white stripes tended to blend together when they travel in packs. To mitigate this, they placed a big red dot on the side of certain healthy zebras they wanted to track. But within days, those red-dotted zebras were eaten by lions.

It turns out that blending in with the pack is a survival mechanism—the Zebra Effect.

Standing out is dangerous. It's always going to be safer and more comfortable to blend in. But it's only by taking this risk that you can accomplish truly remarkable things.

Those from our class who were willing to look crazy for long periods of time had built unique and impactful things.

They also seemed happier on average.

Note 1: There is undoubtedly ​silent evidence​ here (people who had been willing to look crazy and then been eaten by the lions). I met a few. Even accounting for this, those who had taken the risk of non-conformity seemed happy they did.

Note 2: The exception to this lesson were the doctors. They had largely followed the clean track from pre-med to medical school and beyond, but all appeared very fulfilled by their work helping people.

#6: Identity is the real thing we're searching for.

Everyone thinks they're looking for money, fame, or success, but what they're really looking for is identity.

The search for identity is the common thread that connects everyone.

From the athlete transitioning to a life after sports to the founder struggling after selling their company, we all want to know who we are and how we fit into the world around us.

Identity is fluid—embrace it in the present, diversify to lower your risk, and seek out new perspectives to challenge yourself along the way.

#7: Freedom is rare, but incredibly apparent.

There were very few people who seemed truly free.

Those rare few had clearly been intentional about building this freedom into their lives. They had earned it through prior success that untethered them from traditional constraints and then avoided status traps that would have placed them back onto the treadmill.

They weren't the richest or most successful (at least not in the traditional sense of the word), but their energy was infectious.

You can literally see the freedom on their face and hear it in their voice.

#8: We get more embarrassing with age (or we're just mature enough to embrace it).

When I was growing up, I used to wonder why parents were so embarrassing.

I assumed that our parents just had more embarrassing personalities and that we would all be super cool and awesome when we were older and in their shoes.

I was wrong.

We get more embarrassing with age—or, more likely, we just grow up enough to get comfortable with being ourselves.

At the class party, we danced poorly and sang off tune in a way we never would have in our "cool" college stage.

It was beautiful.

#9: Shared struggle builds unbreakable bonds.

This reunion brought together our core group of baseball teammates for the first time in many years. A lot of us haven't kept in touch as regularly as we would have liked, with life responsibilities getting in the way.

But when we were all back together, it was immediately just like old times—everyone telling stories, sharing memories, and laughing until tears were streaming down our faces.

My observation: Shared struggle builds bonds that transcend time and distance.

This observation is grounded in science. Shared struggle releases oxytocin, a chemical that creates feelings of love and connection.

We crawled through the metaphorical (and literal) mud together—navigating 40+ hour practice weeks, challenging classes, and more. Those bonds were forged through suffering, and they are not easily broken.

Find the people you'd crawl through the mud with. Embrace the shared struggle. Cherish them.

#10: Life is much more fragile than you think.

When you're young, you feel invincible. Time is infinite.

We graduated in 2013 with an arrogant surety of what long and bright futures lay ahead of us.

Since then, we've lost several classmates and countless people have lost parents, siblings, or loved ones.

Life has shaken the arrogance out of us.

But amidst the sadness, real beauty has come from it: Everyone is much quicker to smile, hug, and say "I love you" to an old friend.

Life is fragile and time is so precious. Spend it wisely, with people you love, doing things you'll never regret.

I feel extremely grateful for my years at Stanford.

The environment of learning and growth was unparalleled and the people I had the opportunity to meet and build relationships with were particularly special.

I'll leave you with the quote that I wrote in my yearbook upon graduation:

"Go confidently in the direction of your dreams! Live the life you've imagined." ― Henry David Thoreau

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