If you can envision a circle, then you can probably imagine six equally-spaced points along its perimeter (never let them tell you a circle is anything other than polygon with lots and lots of sides). From there it is a relatively simple matter to draw line segments connecting each of these points to two others. Mind you, there are lots of ways to do that, and probability theory can tell you exactly how many ways, but practically speaking, you're most likely to generate either two overlapping triangles or a boring old benzene ring. But if you connect the points according to a somewhat less intuitive rotational symmetry, you'll get a different sort of six-pointed shape, one that is concave and can be drawn with one connected stroke of the pen, id est, without lifting it from the page. The page in your brain, that is, since you're just imagining all this, of course. I take no responsibility for your constructing such a symbol and inadvertently becoming some sort of liar.