The Mole & his Mother
"Why, Mother, you said I was blind! But I am sure I can see!"
Mother Mole saw she would have to get such conceit out of his head. So she put a bit of frankincense before him and asked him to tell what it was.
The little Mole peered at it.
"Why, that's a pebble!"
"Well, my son, that proves you've lost your sense of smell as well as being blind."
Boast of one thing and you will be found lacking in that and a few other things as well.