The explanation is partly the frog-in-hot-water phenomenon (he'll jump out if you drop him in boiling water, but not if you put him in cold water and slowly heat it to boiling).
The idea of slowly heating the water instead of dropping a frog straight into boiling water is what's meant by the phrase "frog in water".
The real explanation has nothing to do with the frog-in-boiling-water phenomenon.
The office is self-funded.
A teacher giving a lecture.
There is an older man.
A fit individual waiting for food to be served.
All domestic violence incidents involve alcohol.
Dolphins are contained in a netted area but sometimes are allowed to swim in the open ocean.