I remember well my first job out of college. The company had hired me as their first-ever editor (I was more like a glorified word processor) and, once they had me, they weren’t quite sure what to do with me. I was miserable there. The work was mind-numbing, and I was left with large swaths of time in which I had absolutely nothing to do.
So I began writing.
And boy, did I get a lot done, even getting published on MediaBistro with an essay I had written during work hours.
I can’t imagine that this is uncommon.