No one really "multitasks" as you would understand it. Actual multitasking is an incredibly inefficient way of doing things, because when a person is focused on more than one thing at a time, they are certain not to do the task in an efficient way.
As a matter of fact, most people CANNOT have more than 1 thought occupying their minds at a time, so most people are not really multitasking. Even if you're in the army and have multiple things to do, seemingly at once, you can't really call that multitasking since you give each specific activity its own time to be done. Even if you're a mother raising 6 children while the father is at work, I can tell you right now without knowing anything about you that you are not constantly focusing on each child individual at the same time. Rather, you think of them collectively as an individual group or you only think of 1 individual child (so either way, they're still being looked at as individuals in some way).
Multitasking doesn't really even exist.
So, when Leonardo da Vinci wrote normally on one subject with his right hand, in
Latin, and at the same time, wrote backwards on a different subject with his left
hand, in Italian, he wasn't multitasking?
Or, when Wolfgang Amadeus Mozart was composing a new work of music in his
mind, and at the same time was writing down a previously composed different
work of music, each of which had different key signatures, and different melodic
themes, one a score for orchestra and the other an SATB motet for small chorus,
and sometimes they were for entirely different purposes (sacred and secular, for
example) he wasn't multitasking?
Or, when an exhibition magician stands on a ball, keeps a stick perched on top of
his nose with a spinning plate on top of it, and juggles three flaming torches with
his two hands, he's not multitasking?
Or, when a cavalryman rides a horse, and shoots a rifle at a moving target, like
at another man on a different horse who happens to be shooting at him, neither
one of them is multitasking?
When a singer thinks about the posture of his legs, hips, back, chest, neck, chin
and tongue, while he considers the amount of air in his lungs compared to the
length of phrase he hopes to finish before breathing again, while he adjusts the
dynamics and tone of the place in his song he's singing based on how he thinks
his last phrase came out in fact and what he expects to do with the rest of the
song, and how the audience is reacting, and whether he is still in tune because
his accompanist is about to start up again after a minute of silence and they had
better be in tune with each other, because the piano can't change its tune -- that's
not multitasking?
When an airline pilot speaks with the Control Tower, reads his 34 gauges (each of
which measure a different thing), sees an approaching aircraft on Port side at
10:00, listens to the co-pilot reporting on the status of the flight crew, and regrets
not having had that additional hour of sleep last night, that's not multitasking?
When a motorcyclist rolls the throttle just a little to lighten the front wheel
enough to skip over a basketball-sized rock, letting the rear shocks absorb all
the impact as he leans to the right and pushes his left handlebar gently forward --
not too much! -- letting the front wheel come down just in time to hit a space
between rocks and at the same time avoids running into another rider who is
trying to pass him up on the trail, that's not multitasking?
Or, when the same cyclist drives his utility van to a race that's going to start in
three hours, as he's cruising down the freeway at 65 mph, steering with his
knees, as he uses both hands to rebuild his motorcycle carburetor on his lap,
and watches for possible unmarked cruisers nearby, that's not multitasking?
Oh, sorry, I should have given examples of women. Okay,
A woman skydiver leaps out of the open cargo bay of an aircraft and looks
for her target on the ground as she checks air speed, altitude and time on her
instruments so that she can pull the rip cord at just the right moment, all the
while doing acrobatic maneuvers in coordination with several other skydivers
who are all doing the same thing, that's not multitasking?