I think the neurological reason would be the emotion you attach to them.
If we were brought up since childhood to believe that 'obsidian' or 'wolves' were curse words, they'd probably cause the same lowered pain response as 'shit' and 'fuck'.
If we were brought up since childhood to believe that 'obsidian' or 'wolves' were curse words, they'd probably cause the same lowered pain response as 'shit' and 'fuck'.