If the Game 2 meltdown felt familiar, there is a reason.

OAKLAND >> Were you surprised by the fact that the Warriors blew a 31-point second-half lead and lost to the Clippers in Game 2 of their first-round series Monday?

If so, you must have missed this team’s regular season.

Yes, 31 is an awful lot of points to choke away — an NBA postseason record, in fact — but in many ways, the Warriors spent 82 games practicing for a moment like Monday’s.

Because if the 2018-19 Warriors’ developed one habit this regular season, it was taking their proverbial foot off the accelerator. Monday night, they turned in their best coasting performance yet, allowing 85 second-half points and being unable to re-engage offensively down the stretch when that massive second-half lead dwindled down to a single-digit deficit.

The Warriors were done in, yet again, by their hubris — the natural and unavoidable byproduct of four straight trips to the NBA Finals and a roster overloaded with talent.

Monday’s loss was another reminder that it’s really hard to three-peat and even harder to win four out of five.

That’s not to absolve the Warriors of their sins Monday. No sir — it’s merely a reminder.

And while the Warriors might be the most talented team in the tournament, they are by no means perfect. This team showed cracks, on and off the court, in the regular season — ones that could expand and leave this team in ruins this postseason.

Some of those cracks re-appeared on Monday.

Ultimately, the Clippers are not going to be the team that razes this Warriors dynasty. Yes, they played an excellent second half Monday — there’s no doubt about that — but in the process, they lost their best asset in beating Golden State: the element of surprise.

So no, Monday night was not the beginning of the end for the Dub dynasty.

But it might have been a sneak preview.

The truth is only one team can beat the Warriors — the Warriors. In Game 2, they showed how refined their self-destructive tendencies are.

The Warriors now have two-plus days to stew in Monday’s defeat — to sit in the embarrassment and anger.

How will the Warriors channel those emotions?

The Warriors find themselves at a crossroads in this series — one that could define this postseason and, in turn, an era.

Will they turn them back on themselves, perhaps expanding those cracks that re-appeared Monday? Or will they use them for fuel to play better ball in the days and weeks to come?

There’s little reason to believe that Golden State won’t handle the Clippers for the remainder of this now-extended series — they did have a 31-point second-half lead, after all — but the remainder of their own mortality in Game 2 could serve as a reminder that they cannot take any win for granted in the postseason.

That’s an important lesson to be taught early on, particularly with the set-up of the Western Conference bracket.

Should the Warriors right the ship and advance, they’ll likely face their rival Houston Rockets in the second round. They don’t want to learn hard lessons about effort in that series, because that team, unlike this Clippers’ outfit, could help them in their self-inflicted downfall.

Golden State wasn’t threatened by the Clippers, so they played loose, uninspired basketball after getting ahead, just as they had done so many times in the regular season. Only this wasn’t the regular season, and the Clippers are not an ordinary team.

L.A. didn’t make the playoffs because they were talented, they made it because they’re ornery and relentless. To them, a 31-point lead wasn’t an insurmountable deficit, it was a challenge.

And by the time the late threat from L.A. became imminent to the Warriors, Stephen Curry and company’s minds were halfway to Tuesday’s off-day and unable to reengage with the opponent who was playing hard to the final buzzer.

One man cannot be blamed for the Warriors blowing a 31-point second-half lead — that’s a team effort and everyone played their part in the historic failure.

Practice makes perfect, after all.