For fun take an American (if you don't have one, they're hireable by the hour). Watch them try to order. You know the way they order, finicking up everything, putting stuff on the side, removing, substituting, over-easifying and the like (they genetically can't just order an item off the menu). You get the one substitution, deal with it. They typically can't. You see them collapse in on themselves, this is the way their world ends, over a bacon sandwich. Then you offer them brown sauce. What is it, they'll plead, why trying to shift their chair backwards so they can bolt for the door but failing because it's wedged into the manky lino floor covering.
It's sauce and it's brown, that's what it is. And a fried breakfast isn't right without it. Plus it can be used to stick things to the table in case of earthquakes.