I've come to realize recently that the word "someday" is an escape word for me. I use it when I don't have an answer or a plan, when the idea of doing or achieving something big seems so far out of my reach that I can't conceive a timeline to accomplish it and I probably don't even have a foothold to get started from.
Though it's something I still find myself doing at times, this habit predates my realization that I tend to work best with set goals in mind. It's certainly an easier cop-out than putting the thought and determination into formulating a way to make certain things happen in my life. However, even if it will take time to accomplish, and certainly the facts and circumstances of getting to the finish line may change, I shouldn't be so fearful that something won't materialize from an idea if I haven't yet started a plan for it. Not everything in life can be easily measured with a timeline.