"What famous philosopher's skull was found to be missing in 1819 when his coffin was opened nearly two centuries after his death? (Hint: the skull itself, now found, has had an interesting history all its own)"
The answer was Descartes, as in Cartesian Philosophy. I highly recommend the book 'Descartes' Bones' by Russell Shorto, which details not only the philosopher's life, but the meandering journey of his body after death and the spread of his ideas up to the modern era. It's a fascinating read, and far more entertaining than one would expect.
Let's return to questions of fashion with this next one, shall we?
Some Victorian mothers, frustrated by their daughters' attempts to loosen (or altogether escape from) their corsets at night during corset-training, took to doing this to prevent them being able to untie themselves.