Alcohol isn't just some magical drink which miraculously feels good to consume. It's a physical substance that affects the chemistry of your brain in some good ways and some not so good ways.
Alcohol is known as a depressive drug, in other words it is a type of drug that slows down your brain. Because your body is used to a certain level of speed, when the messages from your brain are suddenly slowed down and muted, your brain can't keep up with your body, leading to slurring your words and difficulty coordinating movements.
Although this doesn't sound very pleasant by itself, alcohol also increases the amount of a chemical in our brain called dopamine. Dopamine is what makes you feel happy and rewarded. When drinking it can make us feel more impulsive and extroverted.
The problem is that although it makes us more impulsive and likely to take risks, it also reduces our ability to pull off these stunts. Most of the time it just results in hijinks and bad karaoke, but driving is an everyday activity which can become deadly when performed under the influence of alcohol. Here's why:
The first thing to go is your tracking ability, which is what lets you follow a winding road, or understand your position relative to a changing environment. This skill is very sensitive to alcohol use and can be affected even at BAC levels as low as 0.02, well under a standard drink.
At BACs as low as 0.05 it becomes increasingly difficult to divide your attention between multiple tasks, a vital skill when driving.
Approaching 0.08, your watchfulness becomes impaired. Some of your visual functions start to decline, like the ability to shift your gaze between objects and figure out how far away lights are, a necessary skill at night. Our ability to process information from our senses slows not long after. Unexpected things happen on roads all the time, and we rely on our senses such as sight and sound to avoid hazards. When your brain takes longer to interpret and understand what you are seeing, you're more likely to have an accident on the road.
And remember, as a depressant, alcohol will eventually make you feel drowsy. Driving when tired is already a bad enough idea, doing it intoxicated is even worse.
You might not notice any of this changes, but the beauty of alcohol is that makes you less likely to notice that you're not functioning as well as usual. So even if you feel fine and able to drive, it's important to recognise that your ability to safely drive declines even at very low BAC levels. Don't put yourself in a position where you're tempted to take a risk, because your alcohol impaired brain might just think it's worth it when it's not.