Then learn your -ologies!
When I was in college people would always ask me what my major was. I would smile and then proceed to tell them that I was majoring in Anthropology.
Some people would be honest and ask me what that was. To which I would happily reply "people, it's the study of people".
Most people, however, would try and guess what anthropology was:
"Um, what is that? Like the study of ants?"
"Oh yea, like bugs and stuff."
"Wow you must really like rocks!"
Now, when I tell people I'm an archaeologist I get even better responses:
"Oh man I LOVE dinosaurs!" (that would be a paleontologist)
"So have you designed anything in town?" (yep, the guy thought that an archaeologist and an architect were the same thing)
"Cool! Can you tell me about the local rocks?" (Nope, I'm not a geologist)
"You look at bugs?" (Ok, what's up with the bug thing?)
"Indiana Jones!" (Close enough!)
Yep, I guess you can say I'm like Indiana Jones. If Indiana Jones hiked 15 miles a day and watched backhoes dig trenches for a petroleum pipeline.
*And yes, these are all direct quotes*