You're going to find out, you know, one of these years when you start teaching that when you get really close to a blackboard, you just cannot think.

过几年以后,你们渐渐就会发现,当你开始教课,当你离黑板真的很近的时候,你就没法思考了

耶鲁公开课 - 基础物理课程节选