It's a Friday.

Since very early in my youth, because Friday was a half-day at school in kindergarten, my idea of Friday is that it's not really a weekday. I mean, it's not Thursday, and it's certainly not Monday. It's Friday. Friday. Relax and enjoy. "Thank God It's Friday," we say. By lunchtime, the weekend has already started.

My lunch back then (kindergarten) always ended with a Dixie cup -- I think it was chocolate-and-vanilla swirl. To this day, I can still taste, not so much the ice cream itself... but the wooden spoon.

So it's 5:22 right now and as I write I am looking around the office and wondering why am I still here? Why are many of us still here? And it's the weekend now -- so why are you reading this? Because, come on now... it's Friday! I usually don't write on Fridays.

So in an effort to add a little bit of value to this Friday, let me toss out the notion of an additional Rule Breaker attribute. A ninth one. Can it be? Is he suggesting an "official" change to the "Rules"? Is he "Breaking" his own Rules?

Nothing that heady. This is Friday. Take this for what it is worth to you. For me, it's always been implicit, but sometimes we do well to make the implicit things explicit.

There's a guy named Juan J. Campanella, and I want you to know a little bit about him. No, I don't know Juan, personally. There's at least a decent chance that Juan and I may never meet. But Juan posted a single message on one of our discussion boards some months ago that I saved in my e-mail inbox. "A new RB criterium" [sic], Juan called it. I appended a note to myself: "This is a portfolio recap." And so it is, today. And rather than make the mistake of translating Juan's words into my own, I'll just present to you the bulk of his post directly, below. I think we all do well to remember these few paragraphs in our own investing and in life:

I think the ultimate screen for stock-picking an RB is YOU. We are supposed to keep track of the technology, the advancements, the news, the company. You don't want to have to read endless pages of subject matter that don't arouse your interest, that you don't want to learn about. You want to put your money where your mouth is. You want to feel that, when wishing for your stock to grow, your entire heart and being is behind it.

So, choose the RB that works in an area that fascinates you, regardless of owning shares or not. You will be reading a lot about it.

Personally, I can't face a future of reading articles about the advancements of B2B. Superconductivity is interesting, but I realized that I tended to forget everything I read about it as soon as I finished it.

Software Solutions? Not my cup of tea. Biotechnology? That's more like it, I can't get enough of it, but I already own three stocks in that area.... So I was getting desperate.

And then came Ballard [Power] (Nasdaq: BLDP). It fits the RB criteria, and it fits me. I WANT them to succeed. I WANT to know about them. I WANT to know about the technology. It might make ten or twenty percent more or less than others, but my time reading about my companies costs money, too. So that was my Rule Breaker. I bought in yesterday, with my heart.

OK, now, is Juan -- am I -- advocating emotional investing, marrying your stocks, throwing caution to the wind in a fit of passion? Nay, dear reader. Let's get that out of the way, first. Juan (and I, by quoting him) is reminding us all that our portfolios should be natural expressions of ourselves. I have taken to saying recently that I should be able to pick up your brokerage statement and look at your stocks and know therefore a LOT about you. It's just the same as when I might visit your house and go to your den and look at all your books and, therefore, know a lot about you.

Conversely, I don't believe investing in a "good" or "hot" stock that someone else has told you about makes sense, because if you do well it's just luck and not repeatable, and if you do poorly you won't know what to do with the stock and you'll tap in here online with us and ask people what to do. Because you won't know yourself.

And also, what a missed opportunity! You took some of your own very finite life savings (in another way, an extension of you) and put it toward something you didn't particularly understand, that you certainly didn't love. And this is where heart comes in. This is where buying "with my heart," as Juan says, can be at least one sort of check, one good guide (not to be taken out of context because it's just part of the context) for you as you make investment decisions. We can call it the heart check. It's the "do I really care about this thing succeeding?" question. "Will the world be better because of this company? Will I be smiling inside just as I smile outside as this investment becomes a world-beater? Will I love it enough to care?"

I can say about each of the companies in my portfolio below that I do love each one in that way, that I did buy with my heart, and that I do believe the world will be a better place if and when each succeeds. On the other hand, the world will be a poorer place if each does not.

And let's tie it all together: Juan J. Campanella also answers why I'm here in the office on a Friday evening writing, instead of licking wooden spoons somewhere in the woods. It's because I absolutely love what I do. The last day of "work" of my life was the last day of my previous (only previous) job, writing for a financial newsletter. That was April of 1993. Since then, the words "job" and "work" have connoted nothing but fun and, yes, heart.

For most of us, our jobs ultimately mean far more to us than our investment portfolios. I include myself in that group.

I would encourage you, for every time that you check your investment portfolio, to make sure you check around with your job, your family, and your friends, and make sure you're buying -- not just your stocks -- but your whole life with your whole heart.

Happy Friday.
David Gardner

David Gardner is co-founder of the Motley Fool, which is investors writing for investors.