Rightly doing what is wrong

The moth knows he will get burnt.
But he cannot resist the candlelight.

The smoker knows about lung cancer.
But he puffs away day and night.

The terrorist knows that innocent people will die.
But he looks around for a good home for the car bomb.

The diabetes patient knows he should abstain from carbo intake.
But he just have to have his favourite sugar doughnut.

The educated knows that french fries are a good source of trans fats.
But McDonalds serve one of the best french fries.

The married man knows he has a ring on his finger.
But he houses a mistress in a neighbouring island.

The woman knows the man will beat her every night.
But she stands by the man she calls "Darling".

The driver knocked down someone after a good drinking night.
But he speeds off immediately after.

Why do we do something that we know is seemingly wrong?

Or is justification just a lame excuse to satisfy a craving?
To correct a wrong with another one?