Can't call object by name in script?

This seems super simple, but I'm having trouble.

I just want to do something simple to start, like rotation an object through script.. It's very easy to do in the editor, but trying to do it through script I get errors.

First, I created the object in the editor, plopped it in the game space then gave it a name, "guy".

I created a separate script file for guy and executed it in the main game script file.

I did an echo in the guy.cs file to make sure it was working and it was.

Then did something simple like:

guy.setRotation(90);

and I get this:

game/gameScripts/guy.cs (0): Unable to find object: 'guy' attempting to call function 'setRotation'

Seems easy enough, I'm probably just missing some simple yet important step.