As you develop professionally, and grow from an executor to a manager to a manager of managers and so on, the content of your work changes. The skills needed to be a great executor are different from a great organizational manager.
I have always been a proponent of learning by doing. The act of experimenting, testing assumptions, failing, and getting back up again is valuable for developing your personal and professional abilities.
The best product people, I've worked with, are not the ones with the best ideas. In fact, I have found that product people are so focused on understanding and empathizing with problems that they spend far less times talking about solutions.
I've always found it really valuable to have that one friend who challenges you, when the time is right, on the way you think and the things you do.
A big determinant of what you end up doing with your life is how your prioritize your time.
Your company's "core values" and "mission statement" can have a surprisingly large effect on the behavior and performance of your teams.
How much of human behavior can be explained? It is an interesting question, bordering the lines of nature vs nurture, that has no universally accepted answer.
Predicting the future is really hard. We know that humans are generally not very good at it.
It is becoming a bit of an overused phrase nowadays to "optimize for people" - aka always try and surround yourself with the absolute "best" people possible. Sure, we are all striving for that. After all...who wants to surround themselves with the worst people?
Anywhere I have ever worked, whether that be a big company like Uber or super small startup or even school club or basketball team, there is always one person who holds the team together. This person is "the glue."