I spent last evening with a couple friends of mine: Rishad Wadia and Uma Lakhani. We had dinner at an Indian restaurant in downtown Seattle. We were in our own little world when we realized there were people in the restaurant who didn't quite understand what we were saying. It seemed almost Seinfeld... when we realized that we were talking about events and stories and the past using words and terminology completely foreign to everyone else.
I'm sure this happens to most people and it's not super uncommon when nonsensical words make their way into your personal lexicon. We do that in the tech world all the time: "i'll ping you next week"... or "i'll send you a s+". My friends and I were using a very specific word very often: dub. Dub is actually short for "What's the point" and it's a very easy way of describing or rather avoiding topics... it's similar to Elaine's "yada yada yada" in the sense that it avoids unnecessary dialogue and explanation; for example, if I ask Rishad if he wants to play poker... instead of providing a detailed, sometimes bogus, explanation, he simply says "dub". Very simple and effective. It's OK to use these words with your friends... but at some point, these words become part of your common day vocabulary.
At work, I tend to use words like "ping" and "s+" on a daily basis. I also probably use a dozen acronyms or so every hour which is part of the Microsoft culture. I still remember my first couple months when I didn't understand what was going on half the time... and when I asked what a certain acronym stood for, folks would give me the full expansion and then explain how Microsoft employees use a lot of TLAs. :-)