The oppisite of a superstition, a substition is the belief in something that is utterly true. Coined by Terry Pratchett in 'Making Money'.
When my mother told me not to pick at my scab or it wouldn't heal, I saw immediately that she was very substicious (believing greatly in a substition).
The act of switching pillow faces when a pillow becomes too warm due to absorption of the sleeper's body heat. This act can be accomplished by turning the pillow over, revealing the unused and cool side, or by getting a new pillow.
Last night I was pretty hot after doing my girlfriend. So my pillow got really hot and I couldn't fall asleep. That's when I pulled a pillow substitution. It was some tag-team, fresh action.