The odometer on my car hit 107,000 miles, so it was time to take it in for a routine oil change. I know from previous experience the procedure takes about 90 minutes, so I brought an e-book to read and sat in the lobby until the job was done.

Finally, the guy at the counter told me the car was ready, then said something about the battery being a bit low on something I didn’t understand. I assumed he was trying to upsell me a new battery or some super-diagnostic service I didn’t want. So I waved him off saying, “I don’t have time to take care of that right now.” Because being retired with very few commitments or appointments is keeping me so busy.

Exactly three weeks later, the battery symbol on my dashboard suddenly lit up. I’d never seen it before, but it was a rectangle with a plus and minus sign, so I figured it wasn’t a warning about the window washer fluid being low.

I immediately formed a plan: ignore it since the car was still moving. But a half-hour later, my route home took me past the garage that had done the oil change, so I pulled in, parked and turned off the engine. Then I counted to ten, turned the key, and the car started right up.

“Ha,” I thought, “there’s nothing wrong with the battery. What do the experts who make and repair automobiles know?”

Fact: my complete automotive knowledge base consists of ascertaining when the car is low on gas and how to fill up the tank. Not only am I a complete ignoramus about what’s under the hood, there’s only a 35% chance I’ll push the correct button to lower the rear windows on a nice day.

That’s why I abandoned my original plan, got out of the car, and went inside to make an appointment to have an actual mechanic put in a new battery. The guy at the counter said they could take a look after 10am the next day, so that’s when I returned and was told they’d call me once they’d figured out what was going on.

It turned out the problem with the battery was caused by the alternator going bad, and some of the spark plugs were pretty worn down after more than 100,000 miles. I had them all replaced, which cost a not-insignificant amount of money, but it was way less than a new car. I drove my last two cars for over a dozen years and nearly 150,000 miles each, and figured this work would get me to that milestone again.

The chief mechanic agreed. Because what else could he do when facing someone like me, with such a comprehensive mastery of the internal combustion engine?