title_body: How common is it for the creator of a conlang to be fluent in that conlang? This was one of my example questions but I now am actually interested in the answer.  I am an amateur conlanger; I have one pretty complete language and a couple in the process.  But I can't construct a sentence in any of my languages without referencing the lexicon and grammar.  How common is it for the creator of a conlang to be fluent in that conlang? (especially for languages that are not meant to be spoken like all of Tolkien's, where there is not a very significant fluent community).
upvoted_answer: From personal experience (active member in a large server of avid conlangers) very few people ever learn to speak their own conlangs. Language learning is a very time-intensive progress and there is not much gained from learning a language no one else speaks. The occasional exception tends to be found in group projects, in which sometimes at least to a part “creating by using” is used as a technique, which naturally leads to at least rudimentary command of the language. Some languages have also been developed exclusively by using them, such as Viossa, but this is an exception.
  
  You may also be interested in this talk at LCC6, held by Jim Hopkins in his conlang (with an interpreter, of course).  Summary of the talk:
  
  
    In this presentation Jim Hopkins, creator of Itlani, will share his tips and techniques for recording, learning, and living the Language of your Soul. He will discuss the need for finding and ensuring stability in your language’s vocabulary and structure to facilitate easier learning, and how to immerse yourself in your language for mental and emotional engagement, even though you aren’t living full time among native speakers. The presentation will be done entirely in the Itlani language, with interpretation into English by Tony Harris.