The "Apprentice Pillar" that Richard Bridge mentioned is in Rosslyn Chapel, Roslin, Midlothian, Scotland. The legend about it has been linked to Masonic lore and ritual by the people who like to speculate about the origins and purpose of the Freemasons, Templars, etc. The legend could be interpreted as a cautionary tale about seeking perfection, or about excessive decoration.

The myth of Pygmalion is also about a too-perfect sculpture (although it ends happily).

If you have access to a handmade Oriental rug, I recommend you spend some time searching for imperfections—that is, inconsistencies in the regularly repeating elements of the pattern, or violations of strict symmetry. These are often quite subtle, but unmistakable, once you find them. I think you will find it entertaining and enlightening, if you have never done this before. You will probably find, not one, but many of them in one carpet. I don't mean missing or broken threads—that could be the result of wear and tear—but places where the weaver used the wrong color.

Here's a very detailed and informative web site about Oriental and Persian rugs, with lots of beautiful pictures, but Google couldn't find any discussion there of imperfections, irregularities, errors, mistakes, or flaws etc.