Power
Oh, the power of the IRS agent. You hold in your hands power that is almost super-heroic. You wield the fearsome might to make others quake at the thought of handing over their financial records to your scrutiny. You have the power to bring titanic corporations to their knees for making a fraudulent claim. Your ability to identify evil-doers and those who would not pay will nearly warrant a cape.
With this power comes great responsibility (thanks, Uncle Ben!). As an IRS agent, a simple mathematical mistake can bring down a dreaded audit on the innocent, so show your work. A great number of IRS audits are triggered by mathematical mistakes, and you don't want to be that guy.