I know you've heard it a thousand times before. But it's true-hardwork pays off. If you want to be good, you have to practice, practice, practice.

Natural experiments are a powerful tool for understanding causal relationships in the real world.

The eyes of others our prisons; their thoughts our cages.

成功不是终点，失败也不是致命的：重要的是继续前进的勇气。