Since Obi-Wan Kenobi has revealed himself to be a terrible liar, it occurs to me that he might have been exaggerating about what he felt about the destruction of Alderaan:

I felt a great disturbance in the Force, as if millions of voices suddenly cried out in terror, and were suddenly silenced. I fear something terrible has happened.

If you got hit by a superlaser carrying 2 hellajoules of energy at the speed of light, first of all, you wouldn’t be able to see the beam until it hit you, and most importantly, the pain stimulus from getting vaporized wouldn’t reach the brain before you were plasma.