I stumbled upon a website the other day called iamneurotic.com. It's full of weird confessions. And it proves to me that we all have some rather strange idiosyncrasies.

Personal quirks can be endearing. However, they can cost you money if they take the form of investing neuroses.

Candle-wick perfection
For example, someone at iamneurotic.com writes: "I trim all my candle wicks to exactly 1/4 inch. ... [U]nruly flames drive me insane! I like tight, calm, perfect little flames."

Weird, right? Sure -- but many investors obsessively seek perfection in the same way. For instance, if you screen for investments, you might just miss out on lots of decent investments. Let's say you screen for companies in the S&P 500 with net profit margins of at least 10% and expected earnings growth over the coming five years of at least 15%. You'd catch companies such as Akamai Technologies (NASDAQ:AKAM), Juniper Networks (NASDAQ:JNPR), Monsanto (NYSE:MON), and Coach (NYSE:COH). But by arbitrarily using a minimum growth rate of 15%, you're missing out on some solid contenders that might have earnings growth of, say, 14% -- just a little shy of your perfect target. Such companies would recently have included 3M (NYSE:MMM), Abbott Labs (NYSE:ABT), and Goldman Sachs (NYSE:GS).

Similarly, we often try to buy into or sell out of a stock at a perfect price. "It's at $20.75 per share? Well, I'll wait and buy it at $20 or $20.25!" If the stock keeps rising, you'll end up having nickel-and-dimed yourself out of lots of dollars.

Here's another neurotic confession from the website: "Often, I stress myself out by thinking about all my friends, family, and coworkers, and trying to arrange a seating chart for my wedding. I'm single."

That's a funny one, but it reveals someone who's simply looking for things to worry about, and who's focused too much on things that are meaningless today. It's kind of like those of us who watch our stocks' prices a little too closely: "Ooh! 3M is up $0.50 to $77!" or "Rats -- 3M is down $0.12 today. When will it start going up again?"

If you waste ... er, spend time doing this, think about what you're doing. A week from now, will you remember how your stocks moved today? Will it matter much at all a month from now? If you're planning, as many of us are, to hang on to the stock for years, then all that really matters is the price on the day you sell it, which may be far, far away.

The embarrassment test
Here's one last confession: "When I go for runs and listen to my iPod, I am sure that the people I pass by can hear the [bad] music that I am listening to, and judge me for it. … Luckily, this motivates me to run faster."

This makes me think of a portfolio test we might all do well to take. How would you feel if the whole world could see what stocks and funds you own? What if Warren Buffett could see your holdings? And your mom? And your boss? Would they be impressed, or would they shake their heads? Would they think, "She's really grasping at straws there ... she couldn't have done much research into some of those holdings"? Or: "That's a pretty risky portfolio -- I hope it doesn't implode on him"?

Take the embarrassment test -- and then imagine what kind of portfolio would be one you'd be most proud of and confident in. That's the kind of portfolio you might want to build for yourself. I've moved a lot of money from risky high-flyers into mutual funds and blue-chip stocks over the past few years.

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