When it was unveiled a proud Michelangelo stood by and watched as people admired the beautiful Pieta. However, what was pride quickly turned into anger as he overheard a group of people attributing the work to other artists of his time. That anger caused Michelangelo to add one last thing to his sculpture. Going down the sash on the Virgin Mary, Michelangelo carved his name. He later regretted that his emotions got the best of him and vowed to never sign another one of his works again.
In less than two years Michelangelo carved from a single slab of marble, one of the most magnificent sculptures ever created. His interpretation of the Pieta was far different than ones previously created by other artists. Michelangelo decided to create a youthful, serene and celestial Virgin Mary instead of a broken hearted and somewhat older woman.
The Madonna is represented as being very young for the mother of an approximately 33-year-old son, which is not uncommon in depictions of the Passion of Christ at the time. Various explanations have been suggested for this. One is that her youth symbolizes her incorruptible purity, as Michelangelo himself said to his biographer and fellow sculptor Ascanio Condivi:
In 1964, the Pietà was lent by the Vatican to the 1964–65 New York World’s Fair to be installed in the Vatican pavilion. Francis Cardinal Spellman, who had requested the statue from Pope John XXIII, appointed Edward M. Kinney, Director of Purchasing and Shipping of Catholic Relief Services – USCC, to head up the Vatican Transport Teams.  People stood in line for hours to catch a glimpse from a conveyor belt moving past the sculpture. It was returned to the Vatican after the fair. 
The pietà developed in Germany (where it is called the “Vesperbild”) about 1300, reached Italy about 1400, and was especially popular in Central European Andachtsbilder.  Many German and Polish 15th-century examples in wood greatly emphasise Christ’s wounds. The Deposition of Christ and the Lamentation or Pietà form the 13th of the Stations of the Cross, as well as one of the Seven Sorrows of the Virgin.
Pietà is one of the three common artistic representations of a sorrowful Virgin Mary, the other two being Mater Dolorosa (Mother of Sorrows) and Stabat Mater (here stands the mother).   The other two representations are most commonly found in paintings, rather than sculpture, although combined forms exist. 
Dalí occasionally moonlighted as a fashion designer, bringing some of his signature motifs to womenswear. He collaborated with Italian fashion designer Elsa Schiaparelli to create clothing inspired by his paintings, like a dress with drawer-like pockets inspired by The Anthropomorphic Cabinet, a shoe hat inspired by a photo Dalí took of Gala, and a lobster-print dress worn by Wallis Simpson in a Vogue photoshoot in 1937. (Dalí regularly put lobsters in his paintings, often using them to represent his fear of castration.)
Dalí pioneered what he called the “Paranoiac-Critical” method, designed to help him access his subconscious. He described it as a “spontaneous method of irrational knowledge, based on the critical-interpretative association of the phenomena of delirium.” One of the ways he would access this delirious state without drugs or alcohol was to stare at a fixed object and try to see something different within it—much like you might see a shape in the clouds, as the National Gallery of Victoria in Australia explains it [PDF]. Or, he would try to keep himself between sleep and wakefulness, napping with a spoon in his hand and a mixing bowl in his lap. When he fell asleep, the spoon would fall into the bowl, and he would wake up. He would continue to do this in order to keep himself in a semi-conscious, dreamlike state, according to Dalí scholar Bernard Ewell.
The gaps left after all the fragments were in place were filled with replacement pieces made from a copy of statue that had been made from a mould before the attack.
In his attack on the statue, which depicts the Madonna holding the body of the dead Jesus minutes after he was taken down from the cross, the unemployed geologist knocked off her left arm and hand.