%\textfont\bffam=\tenbf \scriptfont\bffam=\tenbf In an undergraduate linear algebra course, one learns about inner products on $\Bbb R^n$. Since the dot product is essentially the only one, they are not very interesting. People actually study a broader class of objects --- {\it symmetric bilinear forms} --- which include what physicists call Minkowski space. The desire to classify symmetric bilinear forms leads to investigating their invariants. This talk will discuss symmetric bilinear forms as a case study to motivate the general theory of cohomological invariants, as presented in a forthcoming book by Serre, et al. A good portion of this talk will be classical in nature, and so accessible to a more general audience.