I've had Facebook for several years and I have seen it go both ways.
Swan--- You are correct that FB can be upsetting and yes, it is just like real life.
There was a time when a friend sort of lived her life by reading what I was doing. She'd tell friends the things I was doing "she went to New Orleans on vacation, she bought a new car"... like she was talking to me, yet I had not spoken to her in years... it really got on my nerves. My sister would read what I did and turn it around, --- that same new car was told to my mother on the phone " she has no business buying a new car, ranted on and on how stupid I was" ... poor Mom, she went with me to buy the car, it was a fun day, did the test drive and I got a good deal... then she had to hear how stupid I was from my sister from out of state... it's upsetting and Mom asked "why did you tell her you bought a car?" we know how she is with anything she hears something is going good for the rest of us. I wanted to just stay away from FB. In the end, I set my privacy settings quite strong and I have a list of people who can not see anything about me, they are on my Blocked list.
When I posted I was having a surgery and very bad recovery, my friends and family posted warm wishes and it really lifted me up. I'd say 98% of my friends are good people who give encouragement and advise. Just Saturday a friend posted on using Cutter spray to kill mosquitoes on her patio, the bottle that attaches to the garden hose... where else could you get advise like that??
I also go each day to FB to play their games. It's enjoyable and entertaining.