I've been self-employed since the pleistocene epoch so I actually don't know how much I'm going to make every year.

After a few years (OK, more than a few) living well beyond my means, I got my finances in order and live well under my "expected" means since then. Some years, like 2008-9, this really saved my ass - and my company. That is something even employees with a steady paycheck can appreciate. If you can manage to live well under your means you are in much better shape when life throws you a curve ball.