Set point?

Hey I just wanted to hear from people who have heard about set point or been told they had reached theirs.  If you find any links in your arsenals, I would love those as well.  I have read some things but it's still clear as mud.  The deal is, I wonder how you know if you are at set point or if you are stalled out?  I have been hovering at or around my current weight for almost ....4 months now?  I have tried changing up my exercise, changing the amount of protein both increasing and decreasing it, and amounts and times i eat.  Honestly, I am okay with my weight even though it is a few pounds shy of my "new" goal weight.  I feel healthy and I look healthy.  I am just wondering what experiences others have had?  My original goal was 190.  I hit that and set another for 170.  I hit that and went after 160.  Met that one and then said, Okay, I am 5' 9" so 150 would be okay.  I lost it and then put some back on (3 to 4) which is when i upped my exercise and balanced out.  Now i am stationary.  Like i said, I am okay with this weight.  I am in the normal bmi range...not by much but normal....and i feel great.  I am on an information and experience expedition here.  Any information is appreciated! 

For me to stay in the 130's means I have to eat less calories, dieting moreso then exercise makes you lose weight.  When I want to lose I take in around 1000 calories, when I want to maintain between 1400-1600.  I could probably maintain at 150 without driving myself nuts with dieting but I feel fat at that weight so its not worth it.  I prefer to be 140 or under.  Last time I weighed back on my birthday I was 139, I doubt I am still there but I won't step on the scale to find out.  lol  It is all a game we play in our heads, whatever weight makes you feel good is the one that you should try to achieve.

At one point I got to 145... and would fluctuate 142-145... But that was a bit low for me.
I wanted to gain 10 lbs... Gained 20... so now my set point is 165-169.  Would not mind losing 10 lbs but I can eat as much as I want (the right stuff = no starchy carbs or sugars), not much exercise, and the weight just stay... If I get higher, I just get less hungry, but last 6 months can't really get much lower than 165.
( I get down to 162.. and back up to 165... crazy) I still have relatively low body fat % ( 24-25%) and size 6-10, so I am not that motivated to lose more.

I don't know if it's scientific or not but for me a set point is a weight I can stay at fairly easily without drastic dieting or depravation.  I have had several over my life, both higher then I liked and lower then I liked.  I have found that if I have to fight to get to or stay at a certain weight then it probably isn't the right weight for me at that time given my activity level and eating comfort level.  Right now I have been at the same weight within 5 lbs for over a year so I figure that is where I am supposed to be right now since I feel like I eat very well and really don't want to eat more or less.