Find something interesting and figure out how it works. The best learning happens when you get in over your head. Once you get sufficiently lost, go back and learn some C. You'll appreciate it more and have a context to apply what you learned.
The kernel code is complicated. Learning C and some CS concepts before diving in will save you a lot of time and headaches. What you could do is learning C and CS while trying to understand some bits and bytes of the kernel, but for that I guess you would need someone else to guide you
If you want to learn that way, you have to be incredibly tenacious. Some people are, some people aren't, but I think my time was better served by learning all the dependencies and then breezing through it when I was in the right place. I mean, you could learn Organic Chemistry and just backtrack to learn Chemistry where applicable, but that's a very hard way of doing it.
I'm not doubting your story, but it's not a hard-and-fast rule. Con Kolivas, who has written some interesting/thought-provoking schedulers for the Linux kernel (and stirred up some politics along the way) had never touched C before jumping in. (http://apcmag.com/interview_with_con_kolivas_part_1_computin...)
At the end you tend to re-invent the wheel if you learn that way. Learning about the existing wheels will save much time and correct a lot of errors that you might never even see when working that way.
And kids knowledge is generally supplemented by adults to complete the picture and sometimes we have to lie to introduce them to some concepts.