Where did the expression 'goose walked on my grave' originate as a name for the shiver you get down your spine?

'Someone is walking over my grave' seems a rather odd thing for a living person to say when experiencing a sudden shudder, so why is it said?

The 18th saying derives from an earlier folk legend that a sudden cold sensation was caused by someone walking over the place that one's grave was eventually going to be.

The expression is sometimes found in the form of 'a goose (or occasionally, a rabbit) walked over my grave'. These are later and chiefly American variants and the 'goose' version at least appears to be a back-formation, derived from 'goose bumps/goose pimples' which are associated with a sudden feeling of chilliness.

The modern-day scientific explanation for sudden unexplained shuddering and for goose pimples is that they are caused by a subconscious release of the stress hormone adrenaline. This may be as a response to coldness or an emotional reaction to a poignant memory. Fanciful it may be, but somehow, I prefer the mediaeval version.