"For some people life is very simple. They decide that this is good, that is bad, this is wrong, that's right. There is not right in wrong, not good in bad, no shadings and grays, all blacks and whites...others find that good, bad, right wrong are many sided, complex things; we try to see every side, but the more we see, the less sure we are." from The Worm at the Core: On the Role of Death in Life by Jeff Greenberg and Thomas A. Pyszczynski
On first glance it might seem that sameness is simple. In reality, I've found it's often much more complex when things are directly oppositional.
Take the color white for example. A short visit to the paint store confirms that there are many, many variations on the color white. Break down the chemical compositions of any two of the simply similarly same whites and you will find a myriad of differences in minerals that create the subtle but distinct tints and hues.
A color wheel shows us that red, yellow and blue, the primary colors, find their opposites in green, purple and orange. In this they are strikingly similar. The opposite of red is green because it is made up simply of blue and yellow; the opposite of yellow, purple because is is only red and blue; and blue's opposite is orange because it is only red and yellow. The pigments that make the primary colors in their purest forms are simply not found in their opposites.
People, thoughts, ideas, opinions, actions...these things of course are much more challenging subjects to understand than colors. All I'm saying is take the time to look carefully because what on the surface may seem the same, may in fact be much more different than you expect.