One reason that people sometimes get arrested on drunk-driving charges is that they honestly did not believe they were so intoxicated that they couldn’t drive. They may have thought they were just slightly buzzed or that they’d had a drink or two and were well below the legal limit. When they get stopped and it turns out that they are too impaired to drive, they’re just as surprised as anyone.
From the outside looking in, people are often shocked by this and act like the drunk drivers chose to do something dangerous intentionally. They don’t know how they couldn’t tell that they were too impaired to drive. But studies have found that it’s actually very hard to know how intoxicated you are at any given moment.
How this happens
There are two reasons that this happens. First, alcohol itself impairs your ability to make sound judgments. This means that you may be less aware of your intoxication the more intoxicated you get. It’s a vicious cycle that works against your own understanding of your condition.
Additionally, people in the studies often just looked at their environment to gauge how sober or intoxicated they were. Someone who was around a lot of other quiet, sober individuals may have felt quite intoxicated, while someone who was in a bar around extremely intoxicated people may have felt that they were nearly sober. This could influence their perceptions so that someone would drive when they actually should not have done so, just because they were a little more sober than the people around them.
If a mistake like this leads to serious charges, make sure you know about all the defense options you have.