Mother Teresa never told us she specialized in neurology

Talented people shouldn't keep quiet about their extraordinary medical skills, which could save lives. Why didn't Mother Teresa, glorified for taking care of sufferers in Calcutta, ever tell us she could intervene successfully in the case of a man with cancerous tumors in his brain ?

The lady was beatified (?) in 2003. And she will be canonized (?) in Rome on September 4 next year. Meanwhile, countless innocent folk have succumbed to brain tumors in spite of the alleged knowledge of the humble lady named Agnes Gonxha Bojaxhiu, who's only starting to be applauded as a great cancer specialist (?) now that she's dead.

Why do otherwise intelligent human beings persist in inventing impossible legends, and then disseminating them as if they were true?