You buy a coffee for a friend, your friend buys one for their significant other, then that person buys a cup for the guy in line behind them and so on Paying it forward just feels really good.
你為朋友買一杯咖啡,你的朋友又為他們的另一半買一杯,然後這個人又為排在他們後面的人買一杯,如此循環往復,這種付出的感覺真的很好。