Sorry, folks. Forever stamps were not the superhero of investments that I thought they were. (USPS)

There are lots of ways to mark the end of the year. My way is to reread my year’s work, deal with mistakes that I haven’t already corrected, and update you on some of the things I’ve discussed.

My most obvious 2016 mistake didn’t involve politics or Donald Trump, topics on which I spent a disproportionate amount of time this year.

My mistake involved . . . postage stamps. I had written, year after year, that Forever stamps were the only thing you could buy that would never sell for less than you paid for them. It was a topic I could discuss in a lighthearted, pun-filled way.

Oops. Because of political paralysis in our nation’s capital, the Postal Service had to cut the price of Forevers to 47 cents from 49 cents. That rate reduction is such a bad idea for such a financially challenged enterprise that I had assumed even in Washington, no one would let it happen. I was wrong.

Moving along: My most foolish mistake was falling so deeply in love with an iconoclastic idea that I failed to check it out properly — and it turned out to be wrong.

Here’s the deal. Conventional wisdom is that the high-profile law adopted during the Bill Clinton administration to limit tax deductibility of certain kinds of executive pay has been essentially useless. So I took great delight in parsing complex data that seemed to prove that the law had, in fact, been useful.

Another oops. Thanks to an astute reader, I realized that I had misinterpreted the data, which I didn’t check rigorously enough because I loved my original conclusion so much. So I wrote a second article, in which I said that the first article had been wrong. The moral: Just because something is iconoclastic doesn’t mean it’s true.

Now a follow-up. In September, I wrote about the bizarre situation in which Charles Biderman, founder of TrimTabs, was ousted by AdvisorShares as manager of the TrimTabs Float Shrink ETF (now Wilshire Buyback ETF) and was starting a rival ETF called — what else? — TrimTabs Float Shrink.

I said I’d track the results of the ETFs, so here they are. From the Sept. 27 launch of Biderman’s fund through Friday, Wilshire had a total return of 11.2 percent, TrimTabs’ was 9.4 percent. Both substantially outperformed the S&P 500’s 5.4 percent.

One thing I did get right, after years of being wrong, was that long-term Treasury bonds finally turned into a terrible investment. Another thing I got right was that it was time to start paying attention to yields on money market mutual funds. Spreads among different funds have widened since the Fed’s recent increase in short-term rates, and I think they will continue to widen.

Now to Trump. I’m a business columnist, not a political pundit, and I generally try not to get caught up in political topics. But because of my experience in dealing with Trump during the 1980s and 1990s — and because my specialty is translating financial gobbledygook into a language approaching English — I devoted a lot of time this year dealing with politics. As they say on Wall Street: When the ducks quack, feed them.

I know that I’ve upset some people by being very critical of Trump, the only person I’ve dealt with in my almost 50 years of writing about business who proudly told me he had lied to me. Yechhh.

He presided over six Chapter 11 bankruptcies, which is why I call him “Donald 66 Trump” rather than Donald J. Trump; and he stiffed plenty of other creditors, as well.

He somehow managed to get big tax benefits on some of his failed enterprises by avoiding “cancellation of debt” income that would have offset most of the losses that he took on his failed enterprises. That seems to have helped him pay little or nothing in federal income tax for years.

I wrote that Trump had accomplished this — as if stiffing the country that allowed your grandparents to come here seeking a better life is an accomplishment — because of something called the Gitlitz decision. But according to Steven Rosenthal of the Tax Policy Center, an astute tax lawyer who’s reviewed documents that I didn’t realize existed, it’s because Trump managed to trade essentially worthless stakes in some of his businesses to creditors in return for canceling debts. I think Rosenthal is right, and I was wrong. If we ever see Trump’s tax returns, we’ll know for sure. I think.

My plan for next year is to spend time — but not an excessive amount — dealing with the substance of what Donald 66 and his billionaire buddies and fellow travelers are actually doing with their new power, not with what they say they’re doing.

And on that note: Whether you agree with me or not about Trump, I wish you and yours a happy, healthy and prosperous 2017.