!!Your role as an imitator
!If you're not a geographer
I'm sure that some people hired at the Helpdesk will actually know what [Arc|?=arcgis] does and maybe if you don't you'll become interested enough in it to take Cartography.  But if not, don't worry, I worked here for two years and never had to explain it to anyone. 
!If you are a Geography Major
Good for you, but don't let anyone know who doesn't know you already. If students need assistance with their projects they can go to their TA's and instructors.  It's just better that way.  
!If you lack Mad Skillz
Don't worry, most of the job involves talking and experimentation.  You can easily pretend you're the greatest Tech Guy in the world by using the internet wisely.

The point is, there is really no need to pretend to be anything you're not when working here.  Most of the only unreasonable expectations you encounter are directed at things which students, staff and faculty take for granted are borderline incomputable.