When someone asks me a question about astronomy, I always have to actively remind myself not to slip into technical terms. This is because science really has, in some sense, its own vocabulary. I can spend hours talking about accretion disks, electromagnetic radiation, parsecs, redshifts, and so on. Unless you are pretty familiar with astronomy and physics, you may not have ever seen some of these terms. This language can at first even be intimidating, but once you understand it, it's freeing.
Scientists use technical language for more than just sounding smart. A lot of the words we use everyday have multiple meanings, or cultural nuances. Using a scientific vocabulary is a way to try and avoid the confusion that arise from that. For example in ordinary language 'light' can be referring to weight, or a light color, or to physical light. So instead scientists use terms like mass, wavelength, and electromagnetic radiation to avoid this confusion. Language is simply a tool for communicating ideas, and some ways of using it are more effective than others.
One of the major problems we have in the U.S. is a lack of science literacy. While some scientists are very good at helping educate the public, many more aren't used to explaining scientific concepts to people other than their peers. Few things can be more frustrating than for someone to be drowned with fancy language when they are trying to learn a new field. To be fair, scientists are not trained as teachers and that's not their job. On the other hand, though, if scientists are going to try and teach their field, they should look into some sort of training.
Sometimes scientists and science enthusiasts like myself forget the downsides to this complex vocabulary. Not only do we sometimes lose people, but it can also affect how our message comes across. Some people hear technical jargon and interpret it as impersonal or cold. When you ask a scientist about their research you are likely to get a long stream of super-technical terms. This is far from cold though. I have yet to meet a scientist who is not excited about their work. Scientists talk this way because they are excited, not because they are dispassionate.
Language is something we use everyday to describe our daily experiences. For a scientist, that day might include smashing high energy particles together, or discovering a totally new species of trilobite. So, the next time you hear a overly technical talk, ask for clarification. Then someday you may catch yourself talking with the accuracy of science.