Welcome to the 1,253 new members of the curiosity tribe who have joined us since Friday. Join the 56,355 others who are receiving high-signal, curiosity-inducing content every single week. Also be sure to follow and subscribe to my new podcast—Where It Happens—and join our 3,000+ person community on Discord!Today’s newsletter is brought to you by Trends!Trends is my personal cheat code for generating new business ideas.It’s a premium newsletter from The Hustle that deconstructs the secret sauce of interesting businesses, side hustles, and emerging opportunities—and gives you the playbook to pounce on them. Even better, membership provides instant access to an exclusive community of 15,000+ entrepreneurs who are building the future.I learn something new from every single issue—it has become a core part of my content and learning engine. I can’t recommend highly enough.Use the link below to join—no commitment, no catch, cancel anytime!Today at a Glance:At the end of every year, I sit down and reflect on what I learned. There is no specific aim or purpose to the exercise—the goal is to put on wings, fly up to 10,000 feet, and assess myself and the year that has passed.2021 was a uniquely transformative year for my life. So for the first time, I attempted to synthesize that jumble.Today’s piece is the result of that attempt: 21 lessons learned in 2021.21 Lessons Learned in 2021At the end of every year, I sit down and reflect on what I learned.I’ve been conducting this self-reflection exercise for the last 10 years, with varying degrees of structure and rigor.There is no specific aim or purpose to the exercise—the goal is to put on wings, fly up to 10,000 feet, and assess myself and the year that has passed.Generally speaking, the reflection has been free flowing and resulted in a jumble of words and thoughts in a notebook. But this year felt different. It was a uniquely transformative year for my life.So for the first time, I attempted to synthesize that jumble—to abstract the chaos into something simple and coherent.Today’s piece is the result of that attempt: my 21 lessons learned in 2021…Engineered SerendipityI believe that some of what we call "luck" is actually the macro result of 1,000s of micro actions.Your daily habits can put you in a position where "luck" is more likely to strike.Increase your serendipity surface area. Engineer your own serendipity.Pessimists Sound Smart, Optimists Get RichPessimists look at the future and see the doors that are closed.Optimists look at the future and see the doors that are open—and probably kick down the closed doors, too.Surround yourself with optimists—those who believe the future is bright will make it so.The Exponential Growth ChallengeHuman brains cannot fathom the insane power of exponential growth. We consistently underestimate its impact.When you're on an exponential growth curve—stop trying to set specific goals.Strap in, keep your head back, and enjoy the ride.Work Like a LionMost people are not wired to work 9-5.Modern work culture is a remnant of the Industrial Age—long periods of steady, monotonous work.If your goal is to do inspired, creative work, you have to work like a lion.Sprint when inspired. Rest. Repeat.Overestimate a Day, Underestimate a YearWe overestimate what we can accomplish in a day, and underestimate what we can accomplish in a year.To fight this, focus on small daily actions that compound over the long-term.Small things become big things. When in doubt, zoom out.Ruthlessly Eliminate NegativityEveryone has a few negative people in their circle. They tell you to be realistic. They laugh at your ambition.Eliminate this negativity from your life. It's a boat anchor holding you back from your true potential—cut the damn line.Tolerance for UncertaintyHaving a high tolerance for uncertainty is a unique competitive advantage. It prevents you from settling.When we fear uncertainty, we settle to escape its grasp.Tolerate uncertainty for a bit longer—never settle for