"It's just one of seven days.

Do you suppose all the world becomes unlucky one-seventh of the time ?" "It was the thirteenth day of the month," said Ojo.
"Thirteen! Ah, that is indeed a lucky number," replied the Tin Woodman.
"All my good luck seems to happen on the thirteenth.

I suppose most people never notice the good luck that comes to them with the number 13, and yet if the least bit of bad luck falls on that day, they blame it to the number, and not to the proper cause." "Thirteen's my lucky number, too," remarked the Scarecrow.
"And mine," said Scraps.

"I've just thirteen patches on my head." "But," continued Ojo, "I'm left-handed." "Many of our greatest men are that way," asserted the Emperor.

"To be left-handed is usually to be two-handed; the right-handed people are usually one-handed." "And I've a wart under my right arm," said Ojo.
"How lucky!" cried the Tin Woodman.