Being reasonably polite

There was a cat on the mat. Henry felt that he would like to get the cat some fresh milk. A man was whistling something.
'Might be another person's cat,' said the man. 'They might not like you feeding their cat more milk. Maybe it's cat has milk in gut.'
'I'll take your words seriously,' said Henry. 'I think I might need to research things. How other people see their own responses in this world.'
The man thought that Henry was depressed. He made some plans in his own kitchen. Examined his gold watch. The cat was he own cat.