There are a lot of questions in the hiring process that make up an entire psych exam. The part that you’re missing is that being a cop kind of sucks.
People curse you and wish you dead when you show up to help them (after they called).
You see a 16 year old girl with half her head blown off.
You work a case of an infant death.
You work fatality car crashes where a six year old dies because his mother wanted to drink and use cocaine in the middle of the day.
You try to work with and calm down people with mental problems like paranoid schizophrenia.
(these are all personal examples)
One could easily enter this field as a completely normal human being and drastically change in five to 10 years. Perhaps we need to have some follow up testing every five or 10 years to make sure we’re still mentally capable to cope with this job.