15 minutes really being 6 hours sounds like Samadhi, however since I do not know you I am hasty to make any conclusion- but you certainly can.
As for empty king- things arise from the unconscious mind- it could be nonsense, or have some sort of hidden meaning. Either way every person's unconscious mind has it's own language and it is up to you to decipher the meaning.
What does the word empty mean to you on a physical, mental and spiritual level. What does the word king mean to you in a physical, mental and spiritual level?
Try and decipher some meaning from that- particularly relate it to your current situation in your life.