This is the only piece by Mozart written in this tune. It is his personal confession.

It's not easy at all. Some say the Mozart sonatas are too easy for children, but too difficult for adults. I think it is something of both.

This reflects his state of mind.

Confess your sins to the Lord and you will be forgiven; confess them to man and you will be laughed at.

There is no refuge from confession but suicide; and suicide is confession

Confession is good for the soul only in the sense that a tweed coat is good for dandruff--it is a palliative rather than a remedy.