I've gotten used to the "car analogy"...

If computers were cars, I would be a mechanic, only I would have to keep hundreds of completely custom engines running 24 hours a day, 7 days a week, all year long, and be able to dive under the hood and fix things while the engines are still running...

This usually brings people closer to understanding what I really do, but it never makes them appreciate it

Such is life as an SA...