Nobody reads a mystery to get to the middle. They read it to get to the end. If it's a letdown, they won't buy anymore. The first page sells that book. The last page sells your next book.
My father was Catholic, my mother was Protestant, and because of that I got Christened in both churches, so I've got all these names... but my Dad always called me Mick.
If you're a singer you lose your voice. A baseball player loses his arm. A writer gets more knowledge, and if he's good, the older he gets, the better he writes.