I get grief sometimes for using "obscure" words as if I am trying to sound intelligent but the truth is I simply love words and language. There are a plethora of ways to convey a point - one way could be very simplistic and dull, another can be overly expressive and unnecessary but then there is the succinct statement that richly conveys the intent with brevity through the proper choice of words. I honestly believe that what separates us from the animals is our ability to convey entire thoughts through one word. For example most people say something was cheap because the item was inexpensive however, cheap should connotate poor quality which is usually coupled with a low price tag. Every concept from our basic conversations all the way to quantum physics are possible because of language. Most people could understand advanced scientific concepts if they had a contextual glossary to decipher the mumbo jumbo through. Neil DeGrass Tyson does this on the show Cosmos - he presents advanced concepts in language that an every day person can understand. I'm sure when he is hanging out with his buddies they use one word as short hand for a concept that would take several minutes to explain to the average person.
Generally people with large vocabularies are considered more intelligent however I would postulate that it is the large vocabulary which makes them more intelligent not the other way around. I heard a podcast about a deaf guy who grew up in a poor area of Mexico and was given the opportunity to go to school and learn sign language among other things. When he went back to visit his friends he couldn't stand it because it took them 45 minutes to tell a basic story through charades. Each person would tell part of the story but repeat everything else that had already been acted out because their brains weren't trained to connect the train of events like we do with words.
Don't look down on large vocabularies as something pretentious but instead consider it as a way to expand your brain - a micro evolution. You can pick up new words everywhere even on TV. The other day I learned the word breviloquent from the Blacklist (excellent show by the way) and have added it to my internal dictionary. Today I refreshed on recalcitrant and also learned inscucient - both great words that made my brain feel a little less stagnant.