I walked with a friend to the newsstand the other night, and he bought a paper, thanking the owner politely. The owner, however, did not even acknowledge it.

"A sullen fellow, isn't he?" I commented as we walked away.

"Oh, he's that way every night," shrugged my friend.

"Then why do you continue being so polite to him?" I asked.

And my friend replied, "Why should I let him determine how I'm going to act?"