No matter how old we are, life's lessons keep coming. I think I learned or relearned a few more this week.

Normally, I'm a cautious person, especially when it comes to spending money. I do a lot of research and comparison shopping so I can make an informed decision.

What I learned this week is that I can't always trust repairmen. I learned due diligence is always in order. And to put it more bluntly, I learned there are shysters masquerading as helpful technicians.

Last year, my husband's air conditioner broke down. Of course it happened on a sweltering hot day when we were happy to part with our money to get it going again.

The air conditioning repairmen said the system really should be replaced. It didn't seem right to us that a five-year-old system could be that bad so we just had it repaired.

This year, when the technician came to give the air conditioning unit its semi annual maintenance check up, he warned us the thing was going to break down any minute.

"Maybe it will last a day," he said. "Maybe it will go for a week or a month. But that's about it."

He explained the system is drawing too much amperage. At best, that means it's inefficient. At worst, it's dangerous. He even showed us his test gauge to prove it. He wanted to sell us a completely new system.

We got a second opinion by calling another company. My problem is I thought the guy was a technician. Turns out he's a salesman. He examined the air conditioning system and pronounced it "on its last leg." We definitely need an entire new system.

Bottom line: It would cost $6,500 for the best "deal" he could offer.

Before Dave signed the papers, I asked him to get a quote from Joe, the incredibly honest guy who designed and sold me the new heating and cooling system in my home.

Here's where it gets interesting. Joe didn't give us a bid for a new unit. After he checked everything carefully his conclusion was, Dave didn't need a new air conditioner. There were minor problems, he said, that could be taken care of for about $100.

Those who said we needed a new system were trying to take us over the coals, he said.

Just to make sure, he said he was sending his best technician to give another opinion.

When the so-called best technician turned out to be a young woman, I didn't expect much. See that stereotyping based on gender and her tender age.

Here's where another life lesson kicked in, teaching me never to stereotype. She turned out to be the smartest, most competent technician we had seen.

"I'm shocked," she said, as she urged Dave to put his hand inside the unit to feel what every guy had missed. "Any technician should have been able to see a part that had fallen."

I won't try to give technical explanations because I'm not good at that. But I did clearly understand when she fixed the so-called problem in a few minutes and firmly said Dave won't need a new unit for years.

When I talked to my brother about the experience, he reminded me salesmen only get paid when they sell. So that's what they do, even if they need to do a con job. He should know. He worked for years selling heating systems.

I hope the entire experience made me a smarter consumer, one less likely to fall for a shyster's line. Hopefully, I'll remember to follow my brother's advice.

"Know the company with which you are dealing and be skeptical when a salesman tries to sell you something," my brother advised.

We're still enjoying the quiet, efficient air conditioning system in Dave's house. And I'm singing the praises of that young woman who really knew her stuff when it came to her job.

I told her I am amazed to see a woman working in her field.

She told us she dropped out of college and became a technician because she always had a mechanical aptitude. She's been at her job for 16 years, she says, and adds that she has seen too many con artists along the way.

Twice this week I misjudged people by their appearance. The first was a toothless, hard-looking motorcyclist with a dirty ponytail. We encountered him while staying at a motel on a kayak trip. I took one look at him and worried he would steal our kayaks.

Instead, he proved to be a sweet guy who watched over our kayaks when we went to dinner.

One much-respected church pastor told me it's a common experience for people to misjudge tough looking motorcyclists. He should know, he said. He is one.

When he's not in his clerical garb, he's on the road with his tough motorcycle buddies. I should mention some are former gang members he met when he was working as a hospital chaplain.

"People treat me like I'm someone to avoid when I'm with them," he said. "It's amazing how we stereotype people."

The lesson I relearned this week is not to be so fast to judge people by appearances.

On the other hand, I also learned not to accept everything a salesman tells me.

Life is one long lesson in discernment, isn't it?