A lot of the things you do in a host culture are things you have to memorize and "just do" rather than coming naturally from your growing up years. It's mentall

A lot of the things you do in a host culture are things you have to memorize and "just do" rather than coming naturally from your growing up years. It's mentally exhausting to keep referring to your catalog of do's and don'ts all day, every day. It doesn't get put onto the back shelf for a great many years.