A + B = B + A = X

A + A = 2A

Ok,, are we are dealing with Variables, we will have case that sometimes A will be Equal to B

A = B

So A + B = X
Subtitute the new value of B (B = A)

A + A = X = 2 A

Oh yeaaah

I don't want to live in this planet anymore

We don't want somebody to tell us that the Sky is blue and it is wrong to be red, cause sometimes it turns to red in the sunset. (Special case)