The interiors of the jovian planets

Yes, those things exist in the inner parts of Jupiter and Saturn and other extra-solar planets of sufficient mass. It is hydrogen that is under extreme pressure. Because the atoms are so close together, their electrons can move freely from atom to atom as they do in all normal metals. In March of 1996, a group of scientists at Lawrence Livermore National Laboratory reported that they had serendipitously produced, for about a microsecond and at temperatures of thousands of kelvin and pressures of over a million atmospheres (>100 GPa), the first identifiably metallic hydrogen.

Sweet action!  Thanks!  It's things like that that blow my mind!  It's just difficult to really conceptualize such materials in anything other than abstract terms, given that we've never experienced things like it in the natural course of events in our lives.

That's true, but everything we see on earth exists for a reason. Still to this day, liquid nitrogen and liquid oxygen astonish me.