Beginner , don't understand logic in simple math : i will go straight to the problem . 
So this bothers me a lot and i know the logic behind it but i seem to not comprehend this logic . You will think of me as a retard but if you can , try to explain me ..

So : when i write in python this
x = 1
x = x + 1

it means x equals 1 (logic) but the 2nd line i was told that it  says , "The new value of x is equal to the old value of x , which is 1 , + 1  "  this bothers me because in math you would not have a "new value of x and an old value of x" cause x will have only one value  and also  i would replace  the first x so it will be like 1 = 1 +1(because they are 2 x-s and i replace both of them with the value of 1 )  which is 1=2 which is non sense but until now that is how i would think about it . I don't know , maybe i'm just dumb.