Saved from a lifetime of trauma
Camping trips are supposed to be joyful activities with friends and family. However, out in the wilderness, things can go awry in an instant. While OP and his family were out enjoying themselves, grandma has this sudden feeling that they need to pack up and leave. Maybe they were used to grandma’s spidey senses because they did just that.
A week later, the OP heard that there was a dead body at the camping site. Imagine being a minor and running into a dead body. Had grandma’s spidey senses been out of sync that day, the entire family might have been traumatized for years.