DS2 (9) has just told me why the sewer system was introduced. Previously, tap water from the Thames contained human waste so they introduced sewers. I had no idea. They are currently introducing a new sewer system in London too, which according to DS2 'looks nice but won't stay like that for long.'
Why am I learning this stuff from a 9 year old? AIBU to be masters level educated but know fuck all about basic stuff like this?
We live in Yorkshire. I don't know how the child knows so much about the Thames anyway.