I get intrigued by words. Today the word was "commit."
When people marry, we say they made a "commitment" to each other (and indeed they did).
Ditto when people make religious vows. Or even when someone decides once and for all to quit smoking! (And so there's an appropriately named product for that very purpose.)
So the word "commit" conveys something of the fullness of the act of will behind a deed or promise. It means that the person is invested in it.
But people also "commit" crimes.
People "commit" sins.
In second grade, I learned that for a sin to be "mortal" (spiritually deadly), there were three conditions, two of which relate to "commitment": knowledge and consent. To the degree that these are present, the whole person is present in the act.
So when we confess our sins, for confession to be valid (never mind spiritually fruitful!), we have to have a "firm purpose of amendment." We have to be just as committed to avoiding the sin (and whatever leads to it) as we were in knowingly choosing to "commit" it. Only this way can we really expect to grow in virtue as a "whole" person.