Why you are not raise this bug in first iteration?

This is hard thing to face such a question by the growing testers.,
The following are the chances to miss the bug:,
1) Functionality of the application incomplete, not stable.,
2) Limited time line, ,
Example:
Dear tester, Start the testing process of this application and update the report before 11.15 am with out fail., ,
Mail sent time: yesterday, 12.00pm, tester come to the office and log on to the system at 9.00am. ,
3)Eager to meet test coverage given time line, with out asking or replying to the mail., ,
4)Only concern with the major functionalities of the system., ,
5)Partially believe on the development team all because of some constrains.,,
Example: Scene 1,
Development Team: Dear tester, this module X is the core pack and we integrate this in to the application., so you no need to concentrate much about this while test with the application., ,
Tester: (in mind: oh, My goodness, then i have to concentrate much in this module, but i don know enough time i get to do test with other things., what to do!!???!!) Okay developer, That module X core pack rite., let me concentrate on other modules in application., why do we spend the billable time with in it..? :) ,
Developer: :) Oh., Sure My dear tester., i know you are doing well at here :) : ) :) ,
Scene 2: later in the iterations, Tester get time to check with the Module X, and her bad time found some bug with in it., This is really bad thing., :( ,
Tester: (In Mind) Not me only do the test with the application.,!! Why this bug not get visible to my fellow testers..???!!!!??? :( (Tester started to cry in Heart Oh! My God., Why i missed this bug..? what will happen when my senior( Senior, even Senior of this tester too not find this bug in application..? This, innocent tester, don know to ask questions like this., so only she cries to the lord, asking forgiveness for her sin.., ) or the client find this bug means., ? ,
Then Tester start to pray:,
Dear Heavenly Father, ,
Have mercy on me., This is the Precious job, given by you from Heaven., I have to be sincere with my work., But am not., i miss one bug and not raise it in Iteration 1 itself., Kindly forgive me., I am having fear and i know fear is a form of death., But am your child., Lord you bring me out from sin, death, dark in to the Life, and Light by your priceless blood., Lord, Kindly guide me, and speck with me what i need to do with this thing., I place all my sorrows, fears, worries upon you Lord., ,
In Jesus Name i pray., Amen., ,
After that tester, had good sleep.,
Day-2 ,
(But in the morning, her mind continuously think about the issue, She try to over come it, she couldn't..,) ,
In morning this line comes in to her heart: Mercy of the Lord Mighty brights me like a shine of sun. She felt good and started to said again and again. After that she did her works went to office., ,
That application came to her desk at 10.30am. She started to test., she feel good and do the test well., and she have no fear while raise that new bug., ,
testing completed., ,
Internal QA bug review meeting with team higher authorities., As usual, higher authority ask this question: ,
Why you are not raise this bug in first iteration?,
....................................................................... Tester have no words to say., ,