A week or two ago I had an awesome lucid dream where I summoned my Dream Guide. (Most amazing experience I've ever had in a dream.) I have had 4 or 5 lucid dreams since then and in everyone I try to summon him again but it never works. Each time it gets worse.

1st attempt: Sky became cloudy and down came my dream guide.
2nd attempt: Sky turned cloudy then stopped and nothing happened.
3rd attempt: Sky turned grey, nothing happened and I felt so stupid that I lost lucidity because I thought it was real life.
4th attempt: Nothing.....

Does anyone know why this is happening and how to solve this problem?