What is the meaning of: “a sword will pierce your soul”? One of the joyful mysteries talks about that after Simeon talked to her, the Virgin Mary took the wound of sorrow and accepted God’s will.  What is that supposed to mean if I am trying to achieve a goal?

Thank you.
The fourth Joyful Mystery of the Holy Rosary is the Presentation of Jesus in the Temple, where the holy man Simeon prophesied that (Luke 2:35) her


  own soul a sword shall pierce, that, out of many hearts, thoughts may be revealed.


The Prophesy of Simeon is the first of the seven sorrows meditated upon in the devotion to the Sorrowful Mother.

In fact, Mary's name in Hebrew, מַרְיָם (Mariam), means "bitter sea".

From Devotion to the Sorrowful Mother:


  The martyrdom of Mary was lifelong, for according to Simeon’s prophecy, she was enlightened with regard to the intense sufferings of her Divine Son. Her entire being was steeped in bitterness. The swords which pierced her soul penetrated also every nerve and fiber of her tender, sinless body. To her was wanting that great support which the martyrs enjoyed in their sufferings. During their torments, they directed their inward gaze toward Jesus, the Crucified, by whose grace and love they were strengthened and consoled. The flames of the love of Jesus cooled the fires of torture, softened the strokes of the scourges, and blunted the sharpness of the sword.