WWWhere is Degenceracy?

I want to find that thing
It fits in every spot
That puzzle piece can go in any slot
Like a master key that is usually a fork
Maybe it is solid
Or not
Could be like cornstarch
It never changes who or what it is
This is not it
But that is what I'm looking for

Image from: http://onthetopofquestion.blogspot.com/2012/09/the-concept-of-art-part-1.html