There is some standard advice you hear offered to writers of every type and sort. “Don’t write unless you have to,” or “If you can not write, don’t.” The idea seems to be that writing is so hard that you shouldn’t do it unless you feel a compulsion to do so, or else that unless you feel that sort of compulsion, you will never achieve any level of skill.
I understand why people say those things. There is even some wisdom behind it, so it’s worthwhile plumbing what they mean by what they say. Don’t write just for the money, for instance. Don’t write to try to impress people. Have something to say. All good advice.
The fact is, though, writing and speaking are so fundamental to success in the modern age that you should find a way to get better at it, regardless of whether you feel “compelled” to write or not. Learn to like it, but don’t use this excuse not to write. (I would argue the same applies to speaking as well, but the learning process is a bit different.)
Let’s differentiate, by the way, between “the muse” and “the compulsion.” Every writer (oversimplification, but close to true) knows that if you wait until you are “moved” to write, you will not produce much. Feeling compelled to write is not the same thing, but in practice it can be similar, because both ideas can keep you from writing.
Almost as truistic is the meme of the writer avoiding writing, the way this cartoonist pictured the creative process within his own profession. If it were true that you should only write if you have to write, then most writers would take it as a convenient excuse to quit.
Even finding something to say is part of the whole process. “I don’t know what I think until I write it down” has been attributed to E. M. Forster, Joan Didion, and Flanner O’Connor, though it’s hard to say who first said it. Forster likely even disagreed with the idea, preferring planning over discovery. But I suspect the widespread and varied attribution results from a common experience: the discipline of putting ideas into words clarifies ideas (with frequent exceptions, of course, as we can witness under the onslaught of babblers).
Like anything else, clear and effective writing and speaking takes effort and thought, and a willingness to be bad at it while you become good. Write. Speak. Do it whether you feel like it or not. It may take quite awhile before your efforts yield a crop. Still: plow your field, plant your seeds. Don’t wait until you feel like it, and don’t wait until you feel compelled.