My distillation of DYJ2 comes from the remarks before the opening sequence, at 1'25": "really? your team is on the wrong side of a 28-3 blowout in the Super Bowl, and you felt like you had control of the game?" That exposition is really what the video sets out to explore.
The fact that such an unbelievable statement could be the genuine feeling of the entire team, and also in fact be true, is what the essence of SB51 is for me. We talked about it live in the gamethread at halftime I think - we had the balance of success in the game. Probably 60-40, maybe 65-35, but more of our plays were succeeding, and Atlanta looked uncomfortable and contained. Now, our failures had failed spectacularly, which had of course contributed to the score. But the score suggested we were getting bullied and humiliated between the whistles, and that just wasn't the case as you watched play after play.
We've all seen the (rare) games where the Pats just didn't have it that night, and an opponent took it to them, a la KC 2014. We had control there of neither the score nor the game. But Bill packs a lot of insight into that remark when he said they felt in control of the game, just not the score. If true, you can reasonably believe that perseverance will bring the score into balance, because it flows from the success of plays and drives. If not, you're delusional and out of your depth. How often is such an optimistic statement delusional rather than prescient? "Just a fool's hope", as it were? 9 times out of 10? 99 out of 100?
I think the lore ought to be that the Pats were the better team - better prepared, better focused, better-executing - and the score merely obscured that until the game's end. This video really helps make that case.