What Schrödinger’s cat REALLY means

This is why it's important to distinguish between quantum-scale stuff and macro objects.  This is why we, who are technically made up of 99.999% empty space, can't just walk through walls.  Of course a whole cat can't be both dead and alive, but an electron can and does exist in probabilistic way.  The other thing is that people often take the whole "observer affects the outcome" to mean that there's some intension behind it, or there's something special about humans, a soul, whatever, that causes the wave function to collapse.  What I don't know is whether it's the interaction between the measuring device and the particle or something akin to relativity which causes the collapse.  Any insight?