Where does it begin and where does it end?

I read a post on another designer's blog recently about the issue of imitation. This subject is something that I (like practically every other artist) has struggled with at some point or other. But now after reading this post and comments I am truly confused about where imitation begins. And, perhaps more importantly, is anything, any design or object style or technique, truly original? And can it really and truly be claimed as the artists original work alone?

My mother-in-law used to tell me when I would question my work "there is nothing new under the sun" and often that was all I needed to reassure me that my work is indeed my own and not a copy of someone else. There is one scenario that stands out, though, where I am not so sure.

Inspired by an item I discovered made by another artist in another medium, I replicated the shape of a certain accessory. It was in another color, it was in a completely different material, and I am sure created by a completely different method. However, I just couldn't get past it. To this day I still feel very much like a fraud for it. And this is even despite all the differences I listed in addition to finding through some research that the shape was not original per se, but a recreation of a style that was popular decades ago.

So then, was I imitating the subject of my inspiration, or the first person to create the particular shape of this accessory more than 50 years ago?

Knitting and weaving are crafts that have been around almost as long as man. But who invented them? Were they invented simultaneously in completely different parts of the world by people who never crossed paths? When I knit or weave am I imitating the art of a "person" who lived thousands or maybe even millions of years ago?

What about techniques? Mobius knitting is rather new in the realm of knitting. If I knit a mobius am I imitating the first person to discover how to knit a mobius? Would I be a fraud if I knit a mobius of my own "design" and tried to sell it?

I recently discovered a new technique of weaving called "clasped weaving" that I am really anxious to try out. Examples I have seen by other weavers are simply stunning and I cannot wait to try my hand at it. BUT, if I do will I be a copycat? A fraud? And what happens when I graduate to a harness loom and start working patterns (houndstooth, chevron, twill, etc.) that have been around for a century or more? Someone invented those patterns, those designs, and now am I to assume that every time I see something woven in one of these patterns that the artist is not an artist at all but instead someone who could not come up with their own just as interesting "pattern" and is now an imitator? And by that measure, even if one were to come up with their own pattern, wouldn't they be imitating the person who first determined that patterns could be devised for weaving? What about the first person who ever wove? Where does it begin and where does it end?

For now I am seriously confused. Situations like this do nothing to reaffirm my confidence in myself as an artist, but rather make me question my own validity and feel positively unoriginal. Sigh.