People would be surprised if they knew how many young kids in gymnastics can do the same things this kid can do. He is advanced but not by a whole lot. For me, it's his body that is amazing. He must not eat the American diet.
My daughter started gymnastics when she was 4 or 5. By 6 years old she had incredible strength and the upper body to go with it. The daily gymnastics workouts are long and mostly upper body work. Her ability to stretch was also amazing. When she did a Russian split during stretching excercises, she still hadn't stretched, the coach had to put mats under her ankles for her to feel like she was actually stretching the muscles. Her legs actually formed a V. One stretching excercise had her laying on the mat face down, arms up as if she was superman. The coach would have her grab a stick with both hands, shoulder width apart and the idea was to see how far up and back you could bring your arms. My daughter could bring the stick all the way to her butt. This is like being handcuffed in front and lifting your arms until you are handcuffed with your arms behind your back. My daughter actually rolled her shoulder joints to do this.
There were plenty of other kids who could do amazing things as well. But this Romanian kid does seem to have learned these tricks earier than most.