You'd think that after a while, Scooby and Shaggy would stop being such pussies when they see a ghost or something. They should know it's just someone in a costume. amirite?

by the time they stopped being afraid of ghost, the ghosts were legitimately ghosts? so they were smart to run from the guys in costumes cause it prolonged their safety.

They were just stoned.

It's cause of all the pot they smoked.

That is the exact reason I always hated that show!!!