Check your brakes or you're going to have a bad time.
Many people (especially enthusiasts) forget that the brake pedal is just as important, if not more important, than the gas pedal during a race or casual drive. Even though speed is a virtue in any race, control is of utmost importance. Control saves both lives and precious seconds around a bend. Impulse may have us wanting to crank the wheel hard and forgo the cautionary tale the squealing tires are telling, but it's the most smooth and uninteresting lap that's usually the fastest.
Smooth and uninteresting laps are all made possible by the brake pedal. As useless as it seems, the brake pedal is the one responsible for calming the vehicle down after a bout of straight-line acceleration. The kart racer in this video learns that the hard way.
The driver recording seems to have a smooth enough start and is just slowing down and getting ready to take the first corner when another racer jets out of nowhere at full speed, claims the inside of the corner, and flies into the barrier without any signs of having found the brakes. In this case, the brakes could have been malfunctioning, causing the driver to impact the wall so hard that they were ejected from the kart. In either case, this crash is a perfect example of what happens when there is a lack of control.