Thinking about numbers....?

SO. Maybe a year ago i was sitting in my favorite bakery place and was thinking about numbers and patterns and all that fun stuff. I started going on this one thought that if you start with a number.... "x" (x-1) + (x+1) = 2x. So, (4-1) + (4+1) = 8. It works every time! I'm sure that I am not following any real algebraic rules but you get the jist of it. I thought I was a genius for a half minute or so and pictured my own wikipedia article with my own number theories and blah blah blah. But seriously, is this of any significance? Is this a special formula for something? Has some ancient mathematician already got his name connected to it? Have YOU thought this thought? I dunno i thought it was pretty kool. (and yes I do know that it just cancels back to x + x = 2x). I'm no math genius ( obviously ) I'm just kinda wondering if anybody else is thinking like me? Comments would be nice.