As anyone who has done Physics I at undergrad level would know ... not a good idea to be out in an electrical storm ... one becomes a lightning rod .. good idea, if caught, is to find a depression, lie down, get soaked .. and enjoy the light and sound show.
laying down is exactly the wrong thing to do. Earth has a finite resistance. If lightning strikes nearby, the electric potential gradualy drops in concentric circles around the point of impact. If you are laying stretched out, you will bridge quite a difference in electric potential between your feet and your head (several 10.000 Volts), which will cause a strong current to flow through you. You should squat down, with your feet close together to minimize the difference in potential.