The mitzvah to put up a mezuzah is made up of a number of details treated in a certain manner and combined in a unique fashion.
A person may find these details comprehensible, moving, and intense or perhaps incomprehensible, un-affecting, and alien.
The character of the mitzvah is not related to the individual’s emotion but to the mitzvah’s relationship with God.
It is a sort of code that, once transmitted (whether or not the person performing it has understood it), forges the connection.
–Rabbi Adin Steinsaltz