Propole - I can't explain, nor can anyone else - water is one of the simplest yet most complex naturally occuring compounds, think of this, most materials are more dense in their solid state than when in liquid state (cold,solid steel is more dense than liquid, molten steel), however ice is less dense than water (hence why it floats). Also Hydrogen is a highly explosive gas at room temperature - oxygen is so reactive at room temperature that it will relight a piece of wood that is still glowing, add to this when you add energy to any atom it becomes more volotile, not so when you burn (addition of energy) hydrogen in oxygen - laws of organic chemistry would point the way to a highly volotile gas compound being formed but instead we get water, an inert, non toxic liquid. Also water can exist in 3 different states all at the same time which no other compound or element can, at 0c water can be gas (moisture in the air), liquid and solid.
So you can see that water does not behave as 'it should', but instead has its own rules and characteristics that no other compound portrays.
Everyone understand that ok??