The former nun celebrated her new-found "freedom" by burning a large "funeral pyre" into which she threw all the trappings of her life in the abbey - clothes, rosaries, crucifixes, the lot. 

After the fire had gone out and she began cleaning up the ashes, she was amazed to discover that, despite the prolonged heat of the flames, her clothing was still intact. 

Determined to eradicate the last vestiges of her vestments, she ran over them with a lawn mower -- to no effect. Then she fed them to a paper shredder, only to have the shredder jam. Finally she managed to dissolve them in a vat of acid. 

Why had she encountered so much difficulty? 

Old habits die hard.