Theory behind Fibonacci?

[HARELSDB@xxxxxxx]

In response to some of the posts on this list, I spent some time fooling with
the Fibonacci retracement tool built into Metastock.  I dismissed it in the
past without looking at it, but, it appears there may be something to it.
Does anyone know the theory behind Fibonacci numbers as they relate to
securities?  Do they work just because the technical analysts think they are
going to work and act accordingly or is there more to it than that?

Then again, maybe it doesn't matter why they work as long as they work.

Thanks,

Dan
Pocatello, ID USA