I have been wondering why some people become composers in the first place and I think it would be nice to share your story of how you started composing in this thread.
It seems a little fuzzy all those years ago, but I think it may have been in September of October 2007 when I decided that I wanted to be a composer. I was ten years old at the time. One of the music teachers at my school asked me if I had ever thought about composing and I said that I had not, but it seems like an interesting idea. He asked me to see if I could try and compose a piece for the classes rather unusual ensemble of pitched and unpitched percussion instruments, clarinet, cello, two keyboards, classical guitar ... can't exactly remember the instrumentation but it was something weird like that.
So I went ahead and spent the next three weeks labouring over this extremely silly little motif in A major that I figured out on guitar. It took me the first week to work out what key it was in! Once I finished the whole work (only twenty-bars long, ternary form) I showed it to my music teacher. I can't remember what happened at this point in time, but I know for sure that the piece was never rehearsed or performed at all. But once I had finished that really silly composition I knew for sure that I wanted to write music. It must have been that feeling of accomplishment that you get once you finish something that you spent so much time and effort on. I spent the next fourteen months from November to the end of December 2008 working on my first symphony as well as a few smaller works.
So that's it. That's how I decided on composing music.
Now over to you.