Surround yourself with Smart People
In How to Be an Expert in a Changing World, Paul Graham states:
Surround yourself with the sort of people new ideas come from. If you want to notice quickly when your beliefs become obsolete, you can’t do better than to be friends with the people whose discoveries will make them so.
Make it a point to befriend people smarter than yourself. Challenge your thinking. Do things differently. Follow a different crowd. Pay it forward by passing on your learning to someone else.