Two Sides to None and Each One

A con needs a pro
For it to work out.
So much can go wrong
With half-wit long cons.
Life has to go on,

And some lives, a lot,
Have come up with ways
To boost what they’ve got.
One trick is to split
One’s own life in half,

And one is to split
The whole world in halves.
Apes with words try both.
We split all the time.
Each split holds both sides,

And we split our sides.
One of our best tricks
Is to pick one side,
Think the world of it,
Pack the world in it,

And then split. Catch us,
We’ll ask you to pick
A shell, just a shell,
Two sides to all shells.
One’s none. Can’t you tell?