Yes, and we're talking about conscious thought with context switching; not necessarily subconscious thought. You can drive or bicycle and actively be thinking about that conversation you had yesterday. Both are complex tasks.
The brains of mammals work very differently from the machines we create. We don't understand exactly how, but they are substantially more complex. Just look at how much work goes into writing a machine that can classify photos as cats or dogs; or software that can drive an autonomous vehicle.
Once a certain skill is fully internalized, using it may require no attention at all.
It's similar to growing a coprocessor designed to do this task, load on CPU is reduced and you may also get a small cache to buffer it for a while without losing context even if interrupted.
It has limitations, too complex tasks are hard for brain to make automatically facile.
Or, when you're trying to fall asleep, find yourself simultaneously mentally singing an earworm while thinking about code while trying not to think of some past trauma. It seems an everyday experience to have multiple streams of thought all at the foreground.
The brains of mammals work very differently from the machines we create. We don't understand exactly how, but they are substantially more complex. Just look at how much work goes into writing a machine that can classify photos as cats or dogs; or software that can drive an autonomous vehicle.