Agree, Worra.
The thing is, people post on stuff that affects them. Usually bad. I'd assume all marriages are hellish, all in-law relationships abysmal, and the world is chock-full of CF if I took MN as representative. All those things happen, but I think they're rarer than positive experiences. It's just that nobody will start a thread to say, for example, that FIL and wife came to lunch a couple of days ago, played with the kids so endearingly, were really good company, congratulated us on the food, and brought small yet carefully chosen and appropriate presents for the kids despite also having sent Xmas money, bless them. Yet that happened to us this week. It just isn't very interesting! Similarly, we've had maybe 3 or 4 CF experiences in adult life, 1 with an estate agent (so does it even count?) as set against millions of positive ones. But it was one of the CF ones I started a thread on.
Weird stuff happens to everyone, at times. That's just life. And people have totally different ways of living, and we will always notice and remember the people who do stuff wildly at variance to us. So I notice the MN who was shocked, shocked I tell you that we don't all pull the appliances out to clean behind every month at least, "Why wouldn't you?!" (Cue a bunch of people pointing out that 1) you can harm a fridge that way, 2) the washer is too heavy, 3) they're boring chores and nobody can see behind them anyway...). I also remember the poor woman whose neighbour throws used nappies and tampax in the front garden to fester. That's scarred me, so Lord knows how she copes.
But I don't notice the loads of people who relate routines/neighbours very like my own. You notice outliers, by definition.