Why do you think Macbeth is startled by the witches prediction's in act 1 of Macbeth by Shakespeare
She pushes MacBeth to kill the king and by doing so fulfills the witches predictions.
This is a personal preference question. Only you can answer it. That means you have to read the play and react to it.
Macbeth attempts to act casual about the witches prophecies and lies to Banquo when he tells him he doesn't think about the prediction at all. In actuality, not only is it on his mind, but he is planning to kill Duncan to make the prophecy come true.
According to the Shakespearean play, Banquo and his son Fleance were attacked by three murderers as they wended their way back to an evening banquet at Forres Palace. Fleance managed to escape. But Banquo never got out of the park near the palace. The murderers managed to cut his throat. The murder of the father, and not of the son, was in accordance with the witches' predictions in Act 1 Scene 3. The witches had told Banquo that he never would be king. But they indicated that Banquo would be the ancestor of a long line of kings. And so, in terms of the plot, it was important for Fleance to escape. The murder of the one and the escape of the other put Macbeth ever more in harm's way from the witches. It made him accept the witches' predictions as fact and as fate. And it made it possible for the predictions to come true.
Hecate expresses her anger with the three witches in Act III scene v. She asks the witches why they have helped Macbeth, calling him a "wayward son, / spiteful and wrathful; who, as others do, / Loves for his own ends, not for you." She also says that she is angry that she was not consulted before they aided Macbeth, and she gives the witches instructions on how to lead him to his own distruction by giving him a false sense of security with their predictions.
Macbeth heads home to prepare his household for a royal visit. But he first sends a letter ahead, to give his wife the news of the witches' predictions. He shows up not too long after Lady Macbeth finishes reading his message [Act 1 Scene 5].
That he would be king hereafter. That one was clear. That he would be Thane of Glamis? Not really a prediction, since that had happened in the past and Macbeth knew about it. That he would be Thane of Cawdor? Also not really a prediction, since the King had already named him Thane of Cawdor, which the witches knew but Macbeth didn't. The only thing the witches say in Act I that is about the future is that he will become king. Well, what about Act IV then? You might argue that the predictions in Act IV don't really come from the witches but rather from "their masters", whatever that is supposed to mean. But leaving that aside, the first thing said is "Beware Macduff!". Well, that is no prediction, just a warning. The other two things which are said are both predictions: that Macbeth will not be killed by a man of woman born, and that he will not be defeated until Birnam Wood comes to Dunsinane. These two, and the one about becoming king, are the three predictions made to Macbeth.
The three "predictions" uttered by the witches in Act I Scene 3 of Macbeth are: 1. He is Thane of Glamis (he already knows this), 2. He is Thane of Cawdor (this is true although he knows nothing about it or even about the battle where Cawdor was revealed to be a traitor.) 3. He will be King (This is the only real prediction since it is something which will happen in the future.)
The second predictions of the three witches dealt with threats against Macbeth [c. 1014-August 15, 1057]. The first predictions of Act 1 Scene 3 dealt with Macbeth's seeming destiny. The witches predicted that Macbeth would be promoted to Thane of Cawdor and then to King of Scotland. Their intention was to lure him down the evil road that uncontrolled, raging, greedy ambition would lead him. In Act 4 Scene 1, the witches intended to keep Macbeth on his evil course by a false sense of security about his reign. They led him to believe that he only needed to beware of Macduff. They also made him think that his kingship was bulletproof to men born of women. They specified that his downfall only would happen with the movement of Birnam Wood to Dunsinane Castle. But they gave him no explanations. They didn't link any of the predictions together. The information was given to him in an eerily supernatural setting deep within a cavern. So it was difficult for Macbeth to think of concrete, practical explanations for such incredulous events.
In Act 1 of Macbeth, the witches bury a pilot's thumb. This gruesome act foreshadows the chaos and deception that will unfold throughout the play.
Macbeth is portrayed as a noble man and good general in The king Duncan's army. he changes to a power-hungry man because of the witches prediction of him becoming the Thane of Cawdor. this leads him to believe that their prediction of him becoming king is true, and therefore, is intimidated to kill Duncan