Because they always cheer me up.
The most recent one I've seen this one. The OP said people using school as childcare meant that they didn't value education.
Cue pretty much every poster saying well of course they valued education but the fact it allowed parents to work as their children were being looked after in school couldn't be ignored. This was then followed by a series of nonsensical posts by the OP saying teachers weren't there to look after kids, only her and her husband ever brought their kids up and she never used school as childcare while admitting at the same time, she had vests amount of grandparent support when she was working and also worked while her kids were at school. Complete madness.
https://www.mumsnet.com/talk/am_i_being_unreasonable/5513931-school-as-child-care?flipped=1&page=1