A Pigeon, oppressed by excessive thirst, saw a goblet of water painted on a sign-board. Not supposing it to be only a picture, she flew toward it with a loud whirr, and unwittingly dashed against the sign-board and jarred herself terribly. Having broken her wings by the blow, she fell to the ground, and was caught by one of the bystanders.
Zeal should not outrun discretion.
Aesop