Not meaning to attack or disparage anyone here, but…
I contend that no one can truly multitask. Perhaps some can switch back and forth very rapidly.
No, all human beings have multitasking brains. Think about all the things different parts of your brain are processing simultaneously when you drive a car for example. Your brain is keeping your organs functioning, controlling your breathing and all those other unconscious processes, whilst also processing visual data and responding to it by sending signals to your hands and feet. You can talk about something, think about something totally unrelated, etc while doing all this. The cognitive and 'lower' parts of your brain function separately yet in a co-ordinated fashion.
Experiments have also clearly shown that the left and right sides of the brain do certain things independently and at the same time. It is not like a cpu running Windows and fudgning it by switching very quickly between processes, but is true multitasking.