That's exactly what happened to me, and you're the first person I've ever seen express it.
I was about 10/11 at the time with a Vic20. I spent quite some time with nothing really making sense. No specific memories, just that I didn't really get it and was close to getting bored with the whole thing. My next memory is that suddenly, I got it. One minute I understood nothing, then it all made sense. Some window opened in my mind and understanding flooded through, an experience I can't explain and have never had since.
Here's how my story differs though - Once I was midway through high school I became embarrassed by my affinity with computers. Bit of a social stigma I spent the next 15 years trying to avoid, working all sorts of different jobs trying to fit in somewhere. It wasn't until I ticked over 30 that I was able to admit it (writing code) was the one thing I kept coming back to; the drug I'd been addicted to for the last almost 20 years, but tried to hide from.
And now here I am, almost 40 and I've just got myself a cofounder, we've registered a company and I've spent what's been (so my wife says) a lovely Sunday sweating in the hottest room of the house (the study) working on the beginnings of a new life. And I can't think of anything I'd rather be doing. Sad, isn't it :)