It's really eye-opening.
Similarly, my ex's mom is really controlling. The dad apparently has bad temper. None of the siblings have healthy relationships or have a social circle. Lots of

. The mom was even quoted, by my ex, saying that she wished her children's father was someone else and she married for money/desperation.
Funny thing is, the mother wanted a divorce a long time ago, but stayed for the kids. They obviously did a good job.
Of course, that doesn't take away the pain and frustration associated with moving on and feeling bad for them.