Prep School in the late 00s:
Head known as Headmaster.
Headmaster organising whole school snowball fight across the whole school grounds, tackling children and pelting children with snowballs.
Children standing up when an adult came into the room.
Boarding Housemaster participating in free swimming sessions and lining children up to pick them up and throw them into the deep end - including 12 and 13 year old girls in swimsuits.
Having a bar in the Staff Dining Room (plus having a Staff Dining Room at all).
A culture of kissing your family goodbye at the start of term and catching up with them in the holidays.
A live in alcoholic caretaker.
Girls not permitted to wear trousers and younger boys forced to wear shorts year round.
Drinking alcohol on school residentials (teachers, not children!)
Fundraising dinners where Year 8 children acted as waiters, including serving alcohol.
Teachers who had decades of service in the school getting away with things nobody else would or should (one who smoked on his fire escape between lessons, one who refused to use technology and one who wrote reports purely consisting of things like 'Good work this term.'
Appointing register monitors because registers were big paper books that had to be collected from and returned to the office twice a day, not done digitally.
Walking classes to the village shop on hot days to buy them ice creams on a whim - no permission, no risk assessment, no dairy allergies.
Almost all staff willing to help or join in with anything - any evening, any time, no expectation of time in lieu or payment, no complaints about workload, work-life balance, hours etc. Just good will and genuine enjoyment of the job.
In most ways, I preferred those days!