Peter T., this page should lead you to some reliable information:
http://skepdic.com/fullmoon.html Click here

It includes comments on why people believe lunar/tidal myths even though "many studies have failed to prove a significant correlation".
Reasons people continue to believe:
"the media perpetuates lunar myths,
folklore and tradition, (superstition)
misconceptions,
cognitive biases and communal reinforcement"

So, to reiterate what others have posted, to understand tides you have to understand gravity. The mass of water in a human body is extremely small compared to the mass of water in the oceans.
Here is a bit more on tides and gravity and mass:
=============================
http://www.hawken.edu/ptra/archive/msg00929.html
To: SMCronin@aol.com, ptra@hawken.edu
       Subject: Re: question about tides and gravity
       From: JLRoeder@aol.com
       Date: Thu, 17 Feb 2000 22:50:07 EST
       Sender: ptra-owner@hawken.edu

The tidal effect is the difference between the gravitational forces on unit
masses on opposite sides of a spherical object -- and it can be shown
algebraically, with some approximations, to vary as the mass of the object
divided by the cube of the distance from the object. So the ratio of the
moon's to the sun's tidal effect is

(mass of moon)/(earth-moon distance)^3

divided by

(mass of sun)/(earth-sun distance)^3.

This ratio is about 11/5

Best regards, John Roeder
===================================

Just picture the amount of water in the ocean as one mass compared to the mass of one human body, and that the ocean is completely liquid... your body is not.

And to conclude.... what Amos said.

Alice