Because in "Pay it Forward", they capture this very idea of human networks as exponential functions.

电影“让爱传出去，深刻地描述了,人类网络是指数函数的观点。

哈佛公开课 - 幸福课课程节选

In many ways, the idea was taken from the film "Pay it Forward".

从许多方面，此想法取自电影“让爱传出去。

哈佛公开课 - 幸福课课程节选

Pay it forward is a movement in LA, Mrs. McKenney.

把爱传出去“是洛杉矶兴起的一场运动。

哈佛公开课 - 幸福课课程节选

Are you still going to pay it forward?

你还会向外传递爱吗？

哈佛公开课 - 幸福课课程节选

If you make three people-- or even better, four people a day feel good and they make-- they pay it forward and make four others feel good, and so on and so on.

如果你能让三个人-,甚至四个人度过美妙的一天-,他们会推展，让四人有美好的一天，以此类推。

哈佛公开课 - 幸福课课程节选

Pay it forward. Pay it forward.

把爱传出去。

哈佛公开课 - 幸福课课程节选