A Fifth Dimension?

[Aoi Magi]

Have someone else ask you a random question which you don't know the answer to, then ask the same to your 5th dimensional friend, if he/she/it can answer correctly, there is some more investigation needed, else if it only knows what you already know, then it is all in your brain.

PS: As long as you don't believe in god you are technically an atheist. Also remember, we are humans too (despite what the religious loons claim), hence we reserve the right to have our share or fantasies