If you have nothing but your own experiences to predict the consequences of your encounters with reality than how did you survive your encounters with such things as traffic, poisonous plants, snakes, rabid animals, disease, cold weather, deep water, etc., to write this question. You must be an amazingly lucky person.

So why is everyone so deluded? Why do people think that there is a world beyond their experience?

Likely it’s so everyone can use the experiences of others to predict personal consequences, without getting nose to nose with a rattlesnake, a rabid racoon or personally view the results of philosophers leaping off mountaintops to "prove" there is no world beyond their own experiences.