It's our nature

All the world's a stage,

And all the men and women merely players.

They have their exits and their entrances,

And one man in his time plays many parts...

-William Shakespeare-

As in any play, or book, the characters have  merly human characteristics, they speak, they think, they  act, they are just la you, just like  me. That is one reason   why we read books of any kind,  we feel  connected to the character, not just because we know him from the  begining, but because  he or she does  many things  we would like to do,  does things we do, act like we do (or like we should) and  just  because they are too human to  be in a book.

In this case, as we were reading Macbeth,  maybe we did no feel  like a man who murdered  a king,  but we could feel  the guilt that  he had just after  he  did  it, he became mad, just because of it like  in Act 2 Scene 4 when Macbeth is at a party  just after he killed Banquo, he sees him   in his seat ; he   said : "Thou canst not say i did it, never shake Thy gory locks at me"  and everybody thought that he was  sick, but then ,lady Macbeth  takes him out from the livingroom and talk to him  about it, because  he was too obvious, and the scene continues. In this case,  we can relate  to the scenen when we  fail an exam or  we did something we are not proud of it, and just somebody knows. When we  feel that the feeling of guilt is killing us inside,  the guy or girl will help us to "keep in line" and to keep the secret.

Another case could  be when Lady Macbeth  starts to walk at night and  she says  what she said to Macbeth just after he killed Banquo, because,  this is  a upset  where the guilt is "killing you from inside" and   your  inconciousness  acts  saying what you did not want to reveal, just to take out this feeling of  guilt. In  our case, sometimes it not as drastic as  in the play, but  we do things  inconciously, like movements, gestures, and sounds that we continue to say until  the truth comes out.

On the other hand, when  you know the truth  of anything, sometimes you look for the right moment  to tell it, just like Macduff   used it  against Macbeth,   when he said "I have no words, my voice is in my sword; thou bloodier willian, That terms can give thee out" and their battle  began , where  he reveals other things, that  little by little kill Macbeth (metaphorically speaking), just to end in  a simple fight. Sometimes we, as humans use this,  to arrive at the right moment and time, to tell the exact words   to  hurt  somebody intentionally. For example, when we know  that  our girlfriend or boyfriend has cheated on us,  and  we wait  a bit to see if she or he  tell us the truth,  but as time goes by,   our anger grows up, and we cannot hold the feeling  anymore, so when we  decide to talk, you know  why are you there, and what  will you do to hurt the other person, just like he or she did to you, like a revenge.

In this case, I think  that Shakespeare tried to  show the nature of power and its limitations as a human, because  at some point this is a great responsability that can make us  crazy enough for us to never  be satisfied with it. In this case, recognition brought this,  and  the characters became  the worst, like proud,arrogant and smart to get  it all,  but they did not became  intelligent,  the reason of this is that  if they have been intelligent enough,  they could controll  the situation  and avoid anything of this. Also,  the characters played  many roles at the same time,  because they could  be  the  sweetest person in the world  with somebody, but the worst with somebody else, and this  is a  mascarade  game, where nobody knows who you really are,  including ypourself,  so  you end up with  many things in mind except for  who you are.
In conclusion,  Shakespeare used this play not only to show another perspective from a real fact, but to show what  humans could do just to get a little power, no matter who you are,  or how strong you are. Further more,  this   play , as one of the most played ones,  he wanted to show  a fight for power not between other humans,  but with yourself,  the fight where you discover your goals, and what  you really need to do to get   it ,  or the fight where you  discover yourself, as simple as this,  because as the play flew, the  characters  little by little didn't knew what to do with  the  power that they were reciving, so  it consumed them because the power was  bigger than the one  they were expecting and the way the got into it  was not the best.