Emily Post on Funerals

The most important time for etiquette, she argues, is when one least imagines it should be important, such as during the trauma and stress of a loved one's death.

It's a good point, and not often made. Makes sense. Like muscle memory in physical sport. Being able to perform without thinking about each small move frees one up to respond with finer thought to specific aspects in the moment.

Source: Bartelby.com