根据以下资料回答第39、40题。
 One morning more than thirty years ago, I entered the Track Kitchen, a restaurant where everyone from the humblest ( 卑微的) to the most powerful came for breakfast. I noticed an empty chair next to an elderly, unshaven man, who looked somewhat disheveled. He was wearing a wom-out hat and was alone. I asked if I might join him. He agreed quietly and I sat down to have my breakfast.
 We cautiously began a conversation and spoke about a wide range of things. We never introduced ourselves. I was concemed that he might have no money and not be able to afford something to eat. So as I rose to go back to the counter and buy a second cup of coffee, I asked, "May I get you something?"
"A coffee would be nice."
 Then I bought him a cup of coffee. We talked more, and he accepted another cup of coffee.Finally, I rose to leave, wished him well, and headed for the exit. At the door I met one of my friends. He asked, "How did you get to know Mr. Galbreath?"
"Who?"
"The man you were sitting with. He is chairman of the Board of Churchill Downs."
 I could hardly believe it. I was buying, offering a free breakfast, and feeling pity for one of the world's richest and most powerful men!
 My few minutes with Mr. Galbreath changed my life. Now I try to treat everyone with respect,no matter who I think they are, and to meet another human being with kindness and sincerity.
The author bought coffee for the old man because _____.