Have you ever listened to people speak but not understood what they are talking about ? perhaps there is a term that they keep referring to that you have not heard of ?
Rest assured this has nothing to do with age as often even other young people may not understand what they are speaking about
One great way to get around this is to look up the word on Urban dictionary :http://www.urbandictionary.com/
Urban dictionary is an online dictionary but one that is updated by the public and one which does not have information for regular words in the english language rather it has information regarding new slang terms or words that are in use but may not be understood by everyone.
This site tries to clear up communication issues and will explain some of the stranger terms that you may have heard.
Some of these terms may be crude but many are not and often multiple explanations are given as sometimes different words in different areas can mean different things.