The present is always changing, but the past is fixed.

The best leaders are those who listen more than they speak, and act with both vision and humility.

The greatest weapon against stress is our ability to choose one thought over another.

"The truth is rarely pure and never simple."

随着距离的增加，我们的知识逐渐消失，而且消失得很快。最终，我们到达了模糊的边界——我们望远镜的极限。