Although this may be obvious given people’s mediocre performance, addiction to stimulants, lack of engagement, and the fact that most people hate their jobs, now there’s loads of scientific evidence you can’t ignore.
There’s some interesting research in social psychology explaining how most people form their peer groups. Especially as children and adolescents, but often as adults, people select their friends based on proximity more than anything else.
When you see things from multiple perspectives, you realize you can achieve almost anything you want in far less time than you imagined. Yet most people have fixed and limited views about themselves and what they can accomplish.
If you have a growth mindset, you operate with faith. You believe in something you can’t see. You believe you can actually get better at something, even though that growth is currently only visible in your mind.