SANTA CLARA, Calif. — San Francisco 49ers coach Kyle Shanahan’s memory is long, especially when it comes to the moments when things took a turn for the worse.

That’s why, as his 3-0 Niners sit alone atop the NFC West standings for the first time since the end of the 2012 season, Shanahan is leading the charge to ensure that nobody looks too far ahead.

“That is good, but that doesn’t mean anything,” Shanahan said of San Francisco’s unblemished start. “I’ve been 5-0 and not made the playoffs before, so that doesn’t mean much.”

To support his approach, Shanahan need only go back to 2015, his first year as the Atlanta Falcons‘ offensive coordinator.

Indeed, Shanahan and those Falcons surged to a 5-0 start and were riding high heading into a Week 6 matchup against the rival New Orleans Saints. Atlanta lost that game by 10, barely beat Tennessee the following week, then went into a six-game funk that killed its playoff hopes on the way to an 8-8 finish.

Of course, that’s just Shanahan’s most recent and personal example of the dangers in believing too much in what happens early in the season. Making sweeping judgments of any team at this point is a fool’s errand, as many teams have proved over the years.

That’s especially true under the rules of the new collective bargaining agreement, which leaves less time for offseason workouts and practice and forces more teams to figure things out in the regular season.

Which brings us to the question everyone seems to be asking about the 49ers: Are they actually good, or have the first three weeks been the product of improved luck and playing teams that have combined to start the season 3-9?

Frankly, it doesn’t matter. What has happened for the 49ers in the first three games plus a bye is of little consequence. What matters is what comes next and how what we’ve seen thus far can shape that.

That’s why Shanahan has made it a point to remind his team it’s OK to believe in what it has accomplished so far while also maintaining a sense of perspective.

“It’s both,” Shanahan said. “You’ve got to believe. There’s lots of things that make you believe. You’ve got to believe that you’re good enough, and I think we’ve added some guys that definitely help, and I think guys that have played here know that they’re good enough. They’ve gone and been in a lot of situations. I feel like guys are getting better, and that’s the confidence that helps you believe in yourself.”

With time off for last week’s bye, it would have been easy enough for the Niners (and their fans) to fall into the trap of gauging where they stand based on results around the league. The 49ers have heard constant discussion about how poor the first three teams on their schedule are and how that reflects on them.

But imagine the outcry had the Niners lost to any of those teams. That line of thinking also ignores the fact that 49ers themselves have been a team that is considered a layup by opposing fans in recent years.

Sure, the 49ers beat Tampa Bay by 14 points in Week 1 — the same Bucs team that knocked off the Rams on Sunday in Los Angeles. Likewise, the Seattle Seahawks beat Pittsburgh and Cincinnati by a combined three points, teams the 49ers beat by a total of 28 points.

But the transitive property means nothing in the week-to-week world of the NFL. And while we might not yet know whether the 49ers need to be taken seriously as a contender, we can safely say they are better than they were a year ago.

The early returns on the offseason investment in the pass rush have been good, as the Niners were third in total defense, fifth in yards per play allowed and tied for second in takeaways (seven, the amount they had all of last season) through the first three weeks.

The offense has been more inconsistent, struggling with turnovers of its own, but it also has established a rushing attack that was fourth in yards per game. The Niners posted 32 points per game, good for fifth in the NFL.

Despite the many places where progress has been made, there’s plenty of room to grow.

“We know as a group we can be so much better,” defensive tackle DeForest Buckner said. “We know we can do better on that on all phases … It’s just the little things. It’s executing and just taking care of the ball and getting the ball on defense.”

The 49ers now head into a stretch that includes a big-stage Monday Night Football game against the Cleveland Browns, followed by a trip to take on the two-time defending division champion Rams and a long road trip to play the Washington Redskins. Even more difficult tests loom beyond that.

Will the next three games offer definitive proof of contendership? Not necessarily, but it will make the case stronger one direction or the other.

“We just completed Week 3 — it’s such a long season to go,” left tackle Joe Staley said. “It’s kind of a bummer that we have our bye week so early because we’d love to keep this, to kind of get around the guys and building that chemistry, practicing. Guys getting more reps above them. I feel confident we have the right team to handle that, and come back ready to go after we kind of get our bye week, get our legs back, and get ready to go for 13 more.”