Being "multi-lingual" - can you talk to non-techies?

I had a lot of expectations for this talk, unfortunately they weren't met. I left the talk feeling talked down to by a person that has no grounding in technology, just grounding in the HR/admin side of things. The example she hoped to use of getting people to explain their jobs, hoping they would be unable to do so without using jargon failed because most people can articulate their work to non-technical people. It didn't answer the question of how to handle situations where you give a high level overview (which was all that was suggested) and people ask for more - how to give that without confusing them - that's the hard part. I can explain at a very high level a technology and what it can be used for, but when asked why it can't do something, it is very hard to explain - this is where the breakdown usually occurs.