The Abandoned Convenience Store

Get on any passenger bus that travels a long distance;
 Greyhound is usually a good pick. Anything that's on the road for longer than 24 hours.
 Get a window seat facing west, then stare at the sun, waiting until sunset.
 Just before the sun touches the horizon, close your eyes.
 Hard. Do not turn away, don't look at anything else. Cover your ears if you have to. 
 After a while, you'll notice that the bus has stopped moving.
 That's the signal that you can open your eyes.
 When you do, you'll see a gas station, illuminated only by a few flickering flourescent lights. There will be no sun, no moon, no stars in the sky.
 The convenience store will have its windows boarded up, but the sign will say ‘Open.' If you feel you can't go through with it, get back on the bus, 
 return to your seat, and fall asleep. You'll wake up at sunrise the next day, well on your way to wherever the bus was going.
 If you enter the store,
 the door will slam shut behind you. You will spend an unknown amount of time there, living out your worst nightmares made real.

 If you survive the ordeal without going mad, you will awake back on the bus, as it reaches its destination. Nothing will ever scare you again.

 Some say that after this ordeal, anything else simply pales in comparison. Others say that all that room contains, is all the fear you will ever feel in your entire life,
 and exposing yourself to it all at once keeps you from feeling any more.

 This, however, can only be done once. There are some exceptions to the ability, as well…