The prophecy that the Chicago Cubs would win the World Series in 2015, from the Book of Biff, may have been false, after all. The “Back to the Future” franchise never delivered on its promise of hover boards, either. You can’t believe everything you see.

The modern Cubs might not believe what has happened to them in the first two games of this National League Championship Series, either. They rolled into Citi Field with 101 victories, postseason included, since opening day, and now have lost twice to the New York Mets.

They lost in Game 1 with Jon Lester, who forever proved his postseason mettle by winning all three starts he made for the Boston Red Sox across two World Series. They lost 4-1 in Game 2 with Jake Arrieta, who had been 18-1 over the last four months.

That was an even better stretch than the 1984 joy ride of Rick Sutcliffe. He came to the Cubs in a midseason trade and went 17-1 through his first start in the NLCS. Then he started the decisive game in San Diego — and lost. But the circumstances might have been beyond the Cubs’ control then, as now.

As the hoary legend goes, a tavern owner named William Sianis tried to bring a goat named Murphy to Wrigley Field for the 1945 World Series. The goat was denied entry, and Sianis vowed that the Cubs would win no more.

They lost that World Series — stopping at 101 overall wins, by the way — and the next time they reached the postseason, in 1984, Sutcliffe’s winning run ended at Jack Murphy Stadium. In 2003 — the Year of the Goat, in the Chinese New Year calendar — the Cubs lost to the Marlins in a seven-game NLCS.

And now this: Lester and Arrieta have both allowed homers to the Mets’ October sensation, Daniel Murphy.

“He’s probably the God of New York right now,” said Miguel Montero, the Cubs’ catcher. “I totally respect that.”

Of course, this Murphy and goat stuff is pure silliness, as all curses are. The Red Sox sold Babe Ruth, and the gods allowed them to win again. Keeping a smelly goat from entering a ballpark just seems like sound hygiene, not a reason to disrupt the hardball cosmos.

Theo Epstein, the Cubs’ president for baseball operations, presided over the 2004 Boston champions, so he has seen painful history dissolve on a diamond. You tend to believe him when he says that these Cubs, managed by Joe Maddon, are not burdened by their past.

“If you create a culture where the guys care more about each other than themselves, and they care more about each other than what’s going on in the outside world, I don’t think any of those narratives — no matter how old and stale or historic and resonant and meaningful — matter to anyone,” he said last week.

“All they really care about is showing up, having fun, embracing what it means to be a Cub and playing at their best when it matters most, and I think you saw that here. They pick up on Joe’s energy; they’re out there doing it for each other and the whole organization. Really, the things that are written about us, the pressure, how quiet it sometimes gets in the ballpark when something goes wrong, none of that stuff bothers these guys.”

Fair enough, but that last observation is worth remembering. The series now shifts to Wrigley Field — at once charming, picturesque, boozy and anxiety-filled — for Games 3 and 4, after a workout day. Kyle Hendricks is scheduled to start on Tuesday against the Mets’ Jacob deGrom, a matchup that heavily favors the Mets and underscores their great advantage so far this postseason.

For all of the aces they have faced — Clayton Kershaw and Zack Greinke of the Los Angeles Dodgers, before Lester and Arrieta — the Mets have the deepest rotation, and their starters can match or outperform anyone.

“They’re going to be really, really good, and we’re really proud of as fast as they’ve come and the way they’ve handled themselves this summer,” Mets manager Terry Collins said. “We think we can stack up with anybody.”

The Mets are not the only team whose best pitchers have exceeded their previous career highs in innings.

Arrieta is 29 and extremely fit, with no Tommy John surgery on his medical chart. But until this season, he had never exceeded 176 2/3 professional innings in a season. In 2015, including the postseason, he is four outs shy of 250.

Maddon said the innings could be taking a toll on Arrieta, who was not throwing as hard as usual on Sunday. When that happens, Maddon said, hitters see everything better and breaking balls are not as effective.

“He was not laboring to throw the ball,” Maddon said. “It just wasn’t as crisp as it had been.”

Arrieta said he did not rely on having his best fastball every night. He said Murphy hit a good curveball for the homer, but acknowledged his stuff was not sharp.

“I know I didn’t have the life, the really good life,” Arrieta said. “I knew it wasn’t there.” He added: “You might not have that explosiveness that you’re used to featuring, but that’s what pitching is about, being able to understand what’s happening, how your body’s responding and pitch accordingly.”

After the first three batters — single, double, homer — Arrieta permitted one infield single and two walks, striking out eight. Yet the five-inning outing matched his shortest of the season, and those first three hitters decided the game.

Like Matt Harvey against Lester in Game 1, the Mets’ Noah Syndergaard was simply better: five and two-thirds innings, three hits, one run, one walk, nine strikeouts.

“When they’re hitting their spots, it’s not easy to do what we want to do when they’re doing what they want to do,” said the Cubs’ Anthony Rizzo. “But every pitcher makes mistakes and we’ve just got to capitalize on them.”

As they head home, the Cubs are running out of time to do that.