Why make blunder?

How did you make blunder? Can you learn from your a very bad move that made your opponent task easier to get a rid of your king out of the board? How to avoid from this tragedy move? But if your opponent is a very high rated player far above yours then you are easy to make a bad bad move..lol. May be this is quite different I think in regard to making blunder...what do you think?

GM Larry Evans stated that there is 10 common mistakes made on the chessboard:
1.  Bad Development        6.  Miscalculation
2.  Neglecting the King        7.  Impulsiveness
3.  Misjudging Threats        8.  Pawn Snatching
4.  Ignoring Pins        9.  Creating Weaknesses
5.  Premature Aggression     10. Inattention

Good luck all!    :)