I've been a software engineer for the last 17 years, with the last 11 years having been in management. The further people get in their career the easier it is to forget to stay humble. You can't always be the smartest person in the room. It's statistically unlikely. One of my favorite books I've read is "The Secret: What Great Leaders Know and Do" (not to be confused with "The Secret"). The book covers how you can stay humble in your career, reinvent yourself, value the contributions of others, etc. The fact is that even if you end up in a leadership position, you won't necessarily be the smartest person in the room. Even if you made a great decision for the team years ago, that may not hold up now. Be open to the fact that you're wrong. Be open to change. If you can't do that then you're going to end up set aside as a dinosaur. Adapt. If you don't then you'll be left behind. And be kind, because you never know who you'll work with again. Being smart isn't carte blanche to be an asshole to anyone who isn't as smart as you. You'll likely need them at some point if you stick around long enough.