It's Simply a Riddle

It is all quite simple
A simple mind can see
A fairly simple idea
Creates complexity

It shouldn't be that simple
Surely it mustn't be
The complexity is in
Its own simplicity

A complex mind will make
More work of it indeed
Cancel out each variable
To see it more clearly

A simple mind however
Won't be hard to please
Simply sounding out the verse
Reveals the simple key

Not so complex now
Was just a simple hoax
But better not forget
The simpleton knows