I remember when I was very young (much younger than 21).....there was an old lady(well, tbh she wasnt that old-probably in her 40s-but back then anyone older than 25 was old)...anyway.....she was pleasant enough. Not exactly the outgoing type, but if you said hello, she would reply and if you waved, she would smile and wave back....just sort of average...but nice enough. She was sitting on her porch one day and she had some hand sewing she was working on and me being the shy type...took me forever to work up the courage, but finally I did...and I approached the edge of her property and called out..."Hi!"......waited for some kind of response, got none.....walked just a little closer....again ...."Hello?"......no response....was getting a little nervous by now, but still went in a little closer...."uh, Hi?".....well...she kind of jerked up like I had startled her...and came out with..."YOU ARE TRESPASSING....GET OFF MY PROPERTY BEFORE I CALL THE LAW ON YOU!!!!".....well ....I of course, skedaddled...eyes brimming with tears and a shock that left me trembling. It took me days to get over it....and I actually thought I was going to be scarred for life...(ya know how dramatic kids get)....BUT...as it turns out, she had a mood disorder which back in those days, was virtually unheard of and had been left untreated. And because of this illness, had gotten behind in her house payments and had foreclosure looming (small town gossip...but this time it was true) and her husband of 18 years, who could no longer take the ups and downs had left her...and I'm pretty sure (but dont know really) that her old faithful dog..."Bojangles"he was called...had passed away. So....in light of all this, it made perfect sense to me that she was a little "unstable" at the time that I made my greeting. I try not to make judgements against people based on their reactions at that given moment...they might have things going on in their lives that make them less pleasant than they usually are.....