Ever screw up so badly that all you could do later on was laugh about it? It’s a feeling I know well: I screw up multiple times a year … in writing … for thousands of readers to see. Don’t get me wrong, though — I’m not complaining. That’s why, every year, I like to go back and laugh about it in front of thousands of readers too. Revisiting my mistakes not only keeps me humble, but it also helps me avoid making the same blunders twice. So in the spirit of accountability, here are some of the many things I got wrong in 2019.

Let’s start with the topic that’s dominated the headlines over the past week: impeachment. For most of the year, I believed that impeachment was a political risk for Democrats that wasn’t worth taking. In March, for example, I predicted that impeachment would drag on through November 2020 and make it harder for Democrats to defeat President Trump at the ballot box. So far, though, there’s no sign of that: Impeachment is actually more popular than it is unpopular with the American public, and the impeachment process looks like it will wrap up in the next couple months.

Then there’s the litany of things I got wrong about the 2020 presidential primary (and voting hasn’t even begun yet!). Over the course of the year, I was high on the candidacies of Sen. Kirsten Gillibrand (“I could see her pumping some of that money into ads at the right time and having a moment”), former Rep. Beto O’Rourke (“there’s a reason he caught fire in Texas last year”), former Colorado Gov. John Hickenlooper (“he’s run some of the best political ads in recent memory”) and Sen. Kamala Harris (“still has a lot of untapped potential … I also think her prosecutorial background means she has several good debates left in her”). Yet, as you surely know, all four candidates have already withdrawn from the race. In fact, in our most recent dropout draft, I chose former Secretary of Housing and Urban Development Julián Castro first overall but scoffed when politics editor Sarah Frostenson picked Harris (and went on a long tirade explaining why Harris was doing fine!). Castro is still in the race (for now), so Sarah got the last laugh on that one. Overall, I think I talked myself into seeing the best-case scenario for too many candidates, which I should have known was foolish — there’s only room in a primary for maybe three or four serious contenders, and, of course, only one nominee!

One candidate whose rise I did not see coming was South Bend, Indiana, Mayor Pete Buttigieg. In late March, after Buttigieg’s buzzy CNN town hall and one Emerson College poll showing him surging in Iowa, I dismissed the Buttigieg bump as overblown, considering the relative lack of evidence behind it. But several polls released after I published that article showed Buttigieg increasing his support. I should have written a follow-up article acknowledging that.

On the other hand, one story I probably shouldn’t have written was this one about Selzer and Co.’s September poll of Iowa. Although Ann Selzer is one of the best pollsters in politics, this piece broke a cardinal rule of FiveThirtyEight: Never write a story based on only one poll. Sen. Elizabeth Warren’s “lead” (it was actually within the margin of error) in that poll wasn’t all that newsworthy, and the poll did not qualify any new candidates for the debates.

Speaking of Warren, one of my first articles of the year attempted to predict the composition of Warren’s base based on her previous electoral performance. While I stand by my analysis of Warren’s 2018 Senate race in Massachusetts, I’ve grown less convinced of its applicability to 2020. Specifically, I shouldn’t have made the logical leap that Warren’s base in past general elections would also be her base in the primary. (I made the same mistake, though I emphasized it less, in a related article about Sen. Amy Klobuchar’s past performance in Minnesota.) The article found that Warren was relatively weak in white, well-educated suburbs, yet college-educated whites have proven to be a source of strength in the 2020 primary.

“Lanes” — the theory that specific candidates are fighting mini-primaries among discrete groups of voters — were another topic on which my thinking evolved over the course of the year. In February, I declared the lane theory “overrated” because there wasn’t much evidence of it in polls of Democrats’ second choices. But honestly, that was way too early in the race to make an assessment; people were barely starting to tune in. When I took a second look at second choices in July, clearer lanes had emerged. More recently, in building our forthcoming primary forecast delegate model, FiveThirtyEight editor-in-chief Nate Silver discovered that lanes really do exist. That said, they remain much more complicated than they might seem; you can’t just divide the race into moderate and progressive lanes and expect that analysis to serve you well.

I also lost a friendly bet with Nate about how many Democrats would end up running for president (one that inspired us to finally settle on some objective criteria for what makes a candidate “major”!). I thought the Democratic field would not surpass the 17 candidates who ran for Republicans in 2016. Boy, was I wrong — by our count, a total of 27 (!!!) ended up running, although the most in the race at any one time was merely 24. Part of the problem was that I took several people — former New York City Mayor Michael Bloomberg, former Massachusetts Gov. Deval Patrick, billionaire activist Tom Steyer — at their word when they said early on that they weren’t running. The lesson here is simple: Never listen to politicians!

Or, apparently, political analysts.