Before 2007, we called them "pound signs".
In the 20-10s, "hashtags" are part of the vernacular - at least if you're participating in any kind of social media. The first known use of a hashtag was in 2007 when Chris Messina, a former Google employee working in developer relations and as a designer on Google+, Tweeted the first-ever hashtag.
Ideas and inspiration always come from somewhere.
Painter. Musician. Author. Inventor. Builder. It doesn't matter what is being created, the idea for the "what" has to come from somewhere. Great artists express what they see, hear or feel, and they reinterpret it with their own vision.