Why does the human body feel an Electric shock? But in an Electric train during running, we do not feel any shock? why?

Human body is a good conductor for flowing current, current always flow close path , when we touch live ckt , current flow through our body to ground, basically generator star point grounded, if star point not connected with Earth, current not flow body , but capacitance effect is effected, Electric train track grounded, leakeg current flow through track , because current flow always low resistance path , if tracks not grounded, then leakeg current flow our body ,

Humain body is also a conductor and earth can be count as neutral and if touch phase wire then we feel shock. but if humain body only touches the phase wire without in contact with neutral medium then we cannot feel shock.