Bears coach Matt Nagy: Forget all that other stuff I said. Justin Fields is our starting QB!

I don’t pretend to understand how the Bears think, in the way I don’t pretend to understand how a cantaloupe thinks.

So I can’t tell you how coach Matt Nagy went from telling us a few days ago that Andy Dalton is the team’s starting quarterback to telling us Wednesday that, no, strike that, Justin Fields is the starting quarterback, now and forever, amen.

It’s beside the point. Nagy made his announcement, saying it was his decision alone to make the switch to the rookie. Perhaps it came to him in a dream. We’ll leave it to the historians to eventually sift through the strangeness of the last few months, along with all the rubble from the other bizarre situations the Bears have gotten themselves into over the years.

What matters is that we’ve got Fields from now on, for better or worse, in sickness and in health. Now we’ll get to see how he progresses, how good he can be. We’ll get to see if offensive coordinator Bill Lazor’s assumption of the play-calling duties positively affects Fields’ development. We’ll get to see if a substandard offensive line is going to get Fields killed.

It’s your job now, kid. Congratulations and good luck against the Raiders on Sunday. Also, you’ll be without injured running back David Montgomery for at least a month, so get your arm and legs warmed up. You’re pretty much the offense now.

What can Bears fans expect from Fields on Sunday and beyond? Lots of the quarterback on the move, whether by design or out of his own concern for life and limb. And, likely, lots of ups and downs. It should be fun and painful and, one way or another, enlightening.

Fields as QB1 is what loads of Bears fans have pined for, ridiculously so, beyond a point that most rational adults are willing to go. Most of us save our ardor for a true love, usually a spouse or significant other, not a professional football player.

I’m going to miss the daily grinding of teeth from the people who believe that Nagy is evil incarnate and that Fields is the answer to any question in life. These are people who, if you asked them to put their feeling about the head coach in one sentence, would say, “Twenty years, with no possibility of parole.’’

Listening to Fields fans rant about the injustice of Dalton’s very existence has been quite an experience. I’ve never been in a rage room, never seen someone take a sledgehammer to a TV, but I imagine this is what it would look and sound like.

Those folks did get some good news Sunday, when Nagy revealed he had handed the play-calling duties to Lazor. But Nagy lost points when he pushed hard in a postgame news conference the collegial effort of putting together the game plan. His taking credit for the Bears’ offensive success against the Lions sounded like former Bulls coach Jim Boylen going on one of his credit-taking missions. Do I have to tell anyone that’s not a good thing?

Here was the standard Bears fan tweet when Fields was playing well against the winless Lions: “The kid is dropping dimes!!! And, somehow, Nagy still wants Dalton!!!”

It’s possible, and I say this with a helmet on my head in anticipation of incoming missiles, that the Bears still have a better chance to win right now with a healthy Dalton in a game than with Fields. Dalton has seen a lot in 144 career starts. Fields has seen little in two starts.

But I get it. With one eye on the future, you’re more interested in Fields’ continued progress. For the longest time (four whole weeks!), Nagy was staring at the now. He wanted to win games because his job is to win games. He knows if he doesn’t, the Bears will fire him. His thought process might have been as simple as that.

So why the change in his thinking? It’s possible he had a revelation after watching tape of Fields’ performance against Detroit. He saw a strong, accurate arm. We all did. Maybe someone above him “suggested’’ the move, though Nagy denied that at a press gathering Wednesday. Maybe Nagy simply got sick of listening to the public clamoring for Fields.

One thing that social media have magnified is the idea that some people, lots of people even, don’t like to entertain the possibility that they are wrong. So they won’t let go of their opinion no matter what’s playing out in front of their eyes. Custer will bounce back! I’m sure of it!

I think Fields’ supporters eventually will be right that he’s a very good quarterback. But it doesn’t necessarily mean they’re right at the moment.

No need to fret. If it turns out they’re momentarily wrong about Fields, Nagy will still be around to blame.