Do you have line bartenders at your bar? Prep bartenders? Who's your sous
bartender? Restaurants need to have a relatively fixed menu because multiple
people often have a hand in preparing the food. On the other hand, I know of a
few restaurants where I can walk in, order something that's not on the menu,
and get it because I know the guys in the kitchen. As a bartender, you're
implicitly expected to have a knowledge of the base cocktails. You're a lone
warrior -- both server and creator -- not just a cog in an assembly line.