Whenever I get together with my friend Elizabeth from Kansas City, she reminds me of what she contends is the funniest thing I ever said. “Remember that time we were all out for breakfast,” she begins, “and you said, ‘The two jobs I could never do are nurse and prostitute’? That always cracks me up.”

But I wasn’t trying to be funny. I was simply stating that I could do no job, no matter how admirable or earthy, that required me to be constantly responding to someone else’s needs. I didn’t see this as either a good or a bad thing. It was just a fact. It still is.

And yet I can still fall into the trap of thinking that I can ace something that doesn’t resonate with me one bit. Just lately, for instance, I was in a meeting that needed someone to volunteer to be treasurer. The deafening silence of no one coming forth got to me, and I said I’d do it. “How hard can it be?” I figured. I found out: hard! Really, really hard. You see, I could add bookkeeping and accounting to that list along with “angel of mercy” and “lady of the evening.” I took math in summer school so it wouldn’t bring down my grade point average. I went to a college where a logic course could meet the math requirement. It took me an hour-and-a-half, with help, to count all those dollars and nickels and dimes, and decipher what was current and what was past, who was owed what, and how much was to be saved in one fund, and another, and another.

When I showed up at the next meeting, broken in body and spirit, but balanced on the bottom line, another member praised me, saying “It was so good of you to take this on.”

I disagreed. “The only good I see in it is a lesson in never again agreeing to do something that I knew wasn’t right for me.”

“No,” she persisted. “In stretching yourself like this, you’ll see that you can do so much more than you thought.”

She was trying to be nice, but I don’t buy it. The Delphic Oracle didn’t have “Man, Know Thyself” plastered over the door without good reason. When we know ourselves, and conduct ourselves as if we do, we function at a markedly higher level than when we try to be all things to all people, do a mediocre job, and spend time doing it that could have gone toward what we do well. It’s these actions and these projects that can seriously help the world. We didn’t come here from the paradisiacal realms to perform half-baked tasks when fully baked ones—yeasted, risen, crusty, and delicious—are the other option.

The longer I observe life, the more convinced I am that effective people spend most of their time on what they do well and very little of it on what they don’t. Certainly we all have chores to perform that aren’t our favorite and at which we’re less than gifted, but these need to be dispatched with efficiently to make way for using our genuine talents and aptitudes, for fulfilling our mission, for following our star.

Here’s an exercise: Look at your calendar for the next couple of months and note everything you’ve agreed to do that doesn’t make your heart sing (or at least hum a few notes). Fulfill these commitments—you are committed, after all—but don’t make any more of them. You can do great good in the world by using for this purpose the knapsack of aptitudes God gave you before you embarked on this journey. When you venture too far away from these, you risk winding up resentful—and filching an opportunity for service from somebody who got straight A’s in math and who, with another minute to get up his nerve, would have just loved to have been treasurer.

A little something to listen to: Many of your enjoyed my post earlier this month, “Victoria’s Victorious Bailout Plan.” If you’d like to hear a 30-minute talk I did on that topic, you can listen on the Unity of Delray Beach site. It’s under “Sunday services, February 1, 2009.” Happy iPod-ing.