If your eyes
follow the movement of the rotating pink dot, you will only
see one color, pink.
If you stare at the black + in the center, the moving dot
turns to green.
Now, concentrate on the black + in the center of the picture.
After a short period of time, all the pink dots will slowly
disappear,
and you will only see a green dot rotating if you're lucky!
It's amazing how our brain works.
There really is no green dot, and the pink ones really don't disappear.
This should be proof enough, we don't always see what we
think we see.