How Long Homeschooling?

On a mailing list, I was asked "how long have you been homeschooling?" And wrote a long response, but after looking over it again and the responses I got, I want to re-present as the following:

1. 25 years ago was my "Helen Keller moment" of education. In my 10th grade, I was ahead of my class in math (pre-calculus) and was studying at my own pace. I hit a brick wall when I encountered calculus (specifically, derivatives). I had to reread the chapter on derivatives several times (over several days, I'm pretty sure) and then somehow it clicked and I made a break through: I understood how calculus works! It gave me the confidence to pretty much learn anything I wanted to put my mind to. And it started to corrode the assumption I had held from my youth (absorbed from my Japanese parents) that education = school, including the necessary push to be open to home education. [Read more about what I learned since then in my older blog entries.]
2. 19 years ago (or so), I first read about homeschooling and it clicked: All those years since my breakthrough made sense to me. I had been self teaching myself: the essence of home education. [Again read my blog on what changes I made] I also knew from then on that my children would be home educated. And I started reading a lot about home education, philosophies, examples and success stories. I also put money where my mouth is: I started donating money to TRI which supports various rights, including homeschoolers. (Keep in mind that at this point of my life, I had a job but still single and not a girlfriend in sight.)
3. 14 years ago my Japanese wife agreed to marry me in spite of my insistance on home educating our future children. (We already had worked out many (more major) differences before we were engaged, so future educational issues were minor and we believed that we could work it out over time.)
4. My oldest is 12 years old and since I personally believe in unschooling, I could argue that we started our "real" studies at birth.
5. Somewhere around 6-10 years ago (I'll pick the middle and say 8?) is when my wife "bought into" home education, but of delayed academics kind (not on the same page as yours truly but close enough (or closest) to unschooling that I can live with it).
6. 4 years ago was when we first started the formal teaching of our eldest. [Since the formal time is at most 1 hour a day, they are effectively unschooled most of the day...]

So my answer would be: "25 or 19 or 14 or 12 or 8 or 4 years, depending on what you mean by that question: please read my blog to see which answer is appropriate."

[Someone mentioned that compulsory age is when the clock starts ticking (for that author) but as an unschooler, I completely disagree. No government or laws is going to tell me when I start educating my children. As a parent, it is my responsibility and mine alone (with my wife, of course).]