There’s nothing in the world that can substitute for real experience

Follow your passion. As long as you’ve thought through it, and you’ve done the math, go for it and don’t let people stand in your way.

A lot of people say you should love what you do. I agree, but I think it’s more you should love what you’re shooting for.

The key to entrepreneurship is failing really quickly – putting things out there, seeing if it works, and if it doesn’t, diagnosing why and focusing on how to improve it from there

People just aren’t wired to give honest feedback, they’re wired to avoid conflict - "But without the truth, you can't improve"

There is incredible power in having people around you...Trying to do it all yourself is a recipe for not only getting it wrong, but also not being able to get back up

If you look at the Spanish Flu of 1918, it wasn't one flu; it was three massive waves over the course of about a year. That's what happens when you let your foot off the brake—when you get excited, and you think you have this thing under control, and then all of a sudden, everyone starts going back to work. It screws the system. You end up seeing these massive waves again.

I think a big part of knowing you’re right is working as hard as you can to prove you’re wrong

If you ever ask someone to rate something from 1-10, don’t allow them to use a 7

Make sure you’re actually solving a problem

People love to make their lives more difficult than they need to be

Most of the successful people I know have TONS of bad idea – they’re just good at editing them out

I think it's both right to check the power of the most powerful companies, and it's probably wrong to assume that their power is complete. Often, what happens is these very large companies are the ones that cause their own downfall—they trip over their own shoelaces, they don't react to something quickly enough, or they over-complicate their products.

If you want to learn a new skill, there’s nothing like sitting down with a nonfiction book on the topic

For nearly every rule that someone might prescribe. There's probably a counterexample the say leader of which would prescribe the exact opposite.

The right thing to do is sometimes the simplest, and it’s often the most effective

Kevin's model showed that the number of new COVID-19 cases in the U.S. would peak in mid-May.

Often, the best ideas start as super-niche things that only people with money can afford—whether it was the car, telephone, you name it.

By hiring people way better than you…you actually end up creating the best possible team

If something doesn't exist in the world, and it's a problem that can be solved, then that's what you should go do

Timing is everything...the number of amazing ideas that either came too early or too late, you got to have that essential element of timing and it's the hardest to predict

On the many failures along the way of building Instagram - “Every time one of these failures would occur, what was the other option besides getting back up…a desk job?”

Fun fact - YouTube used to be a dating website

Getting knocked down is a really common thing no matter where you are in your career, no matter where you are in your progress of building something

Any system is most constrained by its slowest process

How companies grow—usually by word of mouth—mirrors how epidemics grow based on contact between people.

Don’t try to write for the entire world