Isabelle: So what is original?

At what point are things considered original, and even further, how can you distinguish a remix from an improvement to an existing entity? What are the breakpoints between original, to progress, to remix? And is there anything past remix? While watching the video, I got a little bit annoyed, not by the overall concept that it was trying to convey, but by the facts they mentioned. The video praises the Xerox Alto as the first modern personal computer, and while it was the first of its type, in that it had a GUI and a mouse, I found it really easy to argue the point that that Alto is just a remix of other, console based personal computers with screens. But again, it could be argued that those console based computers are a remix of other, more primitive personal computers like the Apple II. While tracing this back, I found myself wondering - where does it stop? I could go back and argue that the Apple II is a derivative of a remix of Turing's first computer, but even that can be considered a remix of Ada Lovelace's work, and I'm sure that it can go back even further past that.  If you trace the timeline computers, or really any concept, type of work, or artistic style, it's difficult to separate the original, progress, remix, or even copy. In this sense, how do we classify our own work? Obviously we have influences, and can draw similarities between those works and our own, but can we distinguish between whether we remixed progressed things to a new level? This is something that I always consider once finishing my works. I've accepted the fact that nothing I make is original - its something that seems to be pounded into our heads in pretty much every art class, but it would be very interesting to explore the degree of difference between our influences and our actual work.