It was my worst financial mistake and left me in what seemed like massive debt at 18. Surprise, the problem started with a credit card.

We’re not talking about spare change here. Financial Post’s Garry Marr looks at how taxpayers could get dinged by municipalities’ land transfer tax plans

A teenager with a $1,500 credit limit in 1982 and on vacation with friends in New York City is trouble. (I was working part-time as a bank teller, which facilitated my ability to get credit at the time.)

So what happened? Strangely enough it wasn’t Manhattan that killed me. I had enough cash for the trip, but my buddies burned through their greenbacks quickly and needed my credit for the trip. They immediately paid me back,  on return to Canada, but for whatever reason — I can’t even say to this day — I didn’t use the money to pay my bill.

Interest piled up quickly. The bank manager called me into his office and sweated me out. I didn’t tell my parents. My father, a sort-of-retired accountant, will probably call me up to ridicule me as soon as this story is published.

The manager threw me a lifeline and offered me a loan, at a lower rate. I snuck the Canada Savings Bonds my grandparents gave me out of the house and used them as collateral to get an installment loan. Two years later — remember, no 2.7 per cent prime rate back then — the debt was paid off.

Lesson learned. Never rack up credit card debt again.

The horrible memory came to mind because I’ve been asked to be part of a panel Monday, as part of Credit Education Week. One question I’ll face: What are some of the most frustrating things you have seen people do with their finances?

My teenage dilemma is not unlike consumers seeking a consolidation loan. The problem is that some Canadians end up with more debt. Some people who pay off credit cards, usually tapping into their home equity to increase their line of credit,  just go out and max out those credit cards again. This is the biggest issue with debt consolidation.

Here are another nine ideas that will destroy your wealth and ultimately prove to be very frustrating to fix. I’ll start from the bottom and work my way up, but the rankings are probably open to debate.

Laurie Campbell, executive director of Credit Canada and sponsor of the event, says her personal favourite is the endless collection of loyalty card points that come at an expense. “Wow, you’ve got this card with 10,000 points but you owe $10,000,” she says.

It’s illogical because you end up spending more on interest than you’ll ever earn collecting rewards, but people continue the pattern. It’s one of my pet peeves too, so let’s make it number 9.

8. Impulse purchases. A Bank of Montreal study in 2013 found 21 per cent of men said they made impulsive decisions, compared to 13 per cent of women. If you weren’t looking for it in the first place, do you need it?

7. Not having a budget. Lack of a financial plan can impact almost everything on the list. A recent Ipsos study found 29 per cent of Canadians have never created a budget. No budget means no examination of expenses and spending that could be eliminated.

6. Diversification. It comes back to haunt you when you’ve invested most of your wealth in one thing — and, to me, that includes the housing market. When markets turn, some Canadians always find themselves burned because they were overly exposed to one sector.

5. Counting on an inheritance. Another Bank of Montreal study found 40 per cent of Canadians expect an inheritance to bail them out. It’s a useless plan. Even if you get it in writing, wills can be rewritten. Inheritance is a bonus, not a guarantee. Don’t make them part of your financial plan.

4. Not making enough money. Sure it’s not that simple, but a study by the Canadian Imperial Bank of Commerce in 2013 showed degrees, like engineering, pay 117 per cent more than a simple high school diploma. Fine arts grads earn 23 per cent more. Student debt is rising faster than inflation, making it all the more important to get bang for buck.

3. Not saving for retirement. The Canadian Payroll Association found in a September survey that 76 per cent of Canadians have put aside less than a quarter of what they will need in retirement. Statistics Canada said in 2013 that only about a third of the labour force has a registered pension plan — you need to create your own own retirement plan.

2. Staying single. As my grandfather, the one who gave me the CSBs, once told me: “Two can live cheaper than one.” More importantly, study after study shows that married people are wealthier. An Ohio State University study in 2013 found married couples in long-term relationships are twice as wealthy as their single counterparts.

1. This isn’t a moral judgement — sometimes relationships don’t work anymore — but divorce is the No. 1 destroyer of wealth. Yet it still goes on. The last time Statistics Canada looked at the issue, in 2011, it found 43 per cent of marriages will end in divorce before 50 years.

Some of these mistakes are unavoidable but you definitely don’t want to repeat them — especially the last one.