One day, two friends approached a stall to buy books and magazines. The salesman turned out to serve poorly. His face was frowning. The first person was clearly annoyed at receiving such service. Surprisingly, the second person still enjoyed it, even being polite to the seller. Then the first person asked his friend, "Hey.

Why are you being polite to that annoying salesperson? "

His friend replied, "Why, why should I...