I may have had a close encounter of the 3rd time in 1983 that I did not remember until a specific event happened that triggered the memory. At that time I was 13 years old the other person who may have witnessed this was by great-grandmother who was suffering from severe dementia.

My mother and I were caring for my Great-Grandmother at her home in the countryside.  One evening she began telling us that little men were looking in her window at her and that they were walking on her roof.  We didn't think anything of it other than her mind was playing tricks on her.
She died peacfully, later that year, from natural causes and we eventually moved to another state.  Years later, either 86 or perhaps 87, I saw a book on UFO's.  I picked it up and as I was thumbing through it I saw an artists rendition of a what is commonly refered to as a "Grey".  I was immeditaly flooded with terror and I flashed back to possibly one or possibly two events that happened to me in Iowa on my Great-Grandmothers farm.  Both occurences happened to me when I was home alone and early in the evening and when I was asleep.
I say possibly two events because I "feel" like there was at least two incidents.  I "know" there was 1.
I woke to find at least 2 greys looking at me through my bedroom window.  That window looked out over my Great-Grandmothers roof, her room being an add on to previous construction.  They lifted the window and walked around the bed to myside which was opposite the window but closest the door.  I remember I was trying to yell but I could only croak and groan like my brain no longer understood language.  I was in a waking sleep state.  One of them stayed at the foot of the bed and the other came over to stand beside me and the memory of THEM suddenly ends.
I clearly remeber two nights when I woke from nightmares I could not remember with my mothers headlights shining into my room when she topped the hill, returning fron town with my Great-Grandmother.
It could not have been late because of my grandmothers condition and I think it was fall because it was pitch black outside and I dont recall the chill of spring.
To this day I feel like this actually happened and was not a simple nightmare. What convinces me is how vivid and sudden the recollection came when I saw the picture of the grey.
On a side note there was a movie with Mel Gibson several years ago that happened to be about ET's in Iowa that I watched and experienced great primal fear from.
I am a retired Sergeant from the US Army and was a professional bounty hunter for years, and this memory still causes me to feel uneasy.
I was moved to write because I read a recent article about Navy Jets chasing a UFO and the Pentagon's recent program to investigate.
Do not post my email address publicly.
Witness indicates that the date of the event is approximate.  PD