What you don't see doesn't exists

Why it is so hard and difficult to see the whole board and possible movements there sometimes? This is very common in general for ordinary people in other parts of life too. It's like psychotic situation: you don't see the whole board, the truth. I mean I just saw: Wow: fork! Then I did it and I lost my Knight for free...Human has very narrow observation capasity. 

Easy, you don't follow or have a logical thinking scheme. You need to force yourself to do the Patzerian Checklist (Diakona may help you with that) after which looking for knight forks and visualizing the board will be instict.

And when you see the clock ticting and the pieces not sticting to their squares, everything will be instinctive. ;)

There can be 40 legal moves in a position and often times you only focus on 2 or 3.

Sometimes you eliminate a good move in your head because it seems bad.

Sometimes you find an OK move and get obsessed with it while there was a better move in the position.

Sometimes you want to risk a bad move because it is a very tricky trap.

Sometimes your strategy (your approach to the position) is simply wrong and therefore you don't even consider the good move.

And finally, if you don't do any of the above, you find a good move.

DonaldoTrump: Dont tell me it is easy! It is like you telling me I have very poor brain capacity. Bummer. You make me sad.

Now I maybe partly understand. I have recently been a partial one-sided numbness. Left adversary is little numb, and it is controlled by the right brain and the right brain is important in perceiving. I do not comprehend a chess board's situations allways very well.