Can you remember any of the bad habits you used to have when you were very young? Perhaps, as a baby, you used to suck your thumb . Of course, you do not do that any more, but you can surely remember your mother's efforts to train you. The good habits you now have in such matters as personal cleanliness were part of this early training. We may not suck our thumbs any more, but as we get older we get other bad habits. We can't give them up easily, either.(Anyone who has tried to give up smoking knows this very well!) Each period brings its own problems. In babyhood, it's thumb-sucking; in childhood, it's nail-biting; in our teens, it's smoking; in middle-age, it's over-eating, and so on. And if anyone tells you that he has no bad habits, you can be sure that he must have the worst habit of all. At the end of the story the writer says "And if anyone tells you that he has no bad habits, you can be sure that he must have the worst habit of all". Here what do you suppose the worst habit is?
Reading. Playing. Walking. Lying.