'#' used to be called the pound sign and even the number symbol before people decided it was a 'hash tag.' I for one refused to give in to Twitter's manipulations and refused to call it a hash tag for many years. I spent so much time programming and using this symbol for various functions in different languages that the meaning of the symbol in my mind went beyond its typical use on the internet now. (I also think it looks ridiculous in news reports on TV and in band names or their hit singles, which has nothing to do with my topic but is something that will never stop being hilarious to me) Much like words, the meanings of symbols change and diversify over time. Even the contexts we write in change. Blogging has gone from anonymous people on posting angrily on message boards to 12 year-olds writing bleak poetry on Deadjournal to sharing taste in boy bands on Myspace to fleeing for Facebook when grown-ups figured out how to use Myspace to writing for class blogs in college of all things.
I don't think it's possible for a student in high school to understand how significantly their world is bound to change in just ten years, and this is one reason that I think learning to write well is such an important thing. Writing and contributing to the use of current technologies that utilize communication skills keeps us in the present. From time to time, I hear older people saying they cannot keep up with changes that are happening in our society. This does not seem acceptable in today's world when we have instant access to information. Adaptability is a virtue nowadays. Fortunately for us, command over our language gives us that power. We continue to learn how words and ideas have changes and write about older things in newer contexts. I write because I have to; if I didn't adjust to the changing meaning of everything I'd probably be left in the dust.