Christmas has come early for "Breaking Bad" fans: The "Complete Series" Blu-ray set is in stores today, and it's packed with commentaries and special features to go along with all 62 episodes of AMC's epic drug-trade drama.

But the 99.9-percent pure highlight for fans has to be "No Half Measures," the 2 hour and 15 minute (!) documentary about the making of "BB's" final season. The filmmakers had amazing access to the cast and crew throughout the production of "BB's" final eight episodes, letting us be a fly on the wall (or in the meth lab) as Walter White's long journey from Mr. Chips to Scarface draws to a close.

[Related: 'Breaking Bad' Spinoff Scoop From the Man Who Created Saul Goodman]

You should really watch the entire thing, but here, we've picked out 15 things the documentary taught us about one of the greatest TV dramas of all time.

1. "Breaking Bad" ended right where it began.

That flashback to Walt and Jesse's first cook at the beginning of Season 5's "Ozymandias"? That was the very last thing filmed on the series. We see stars Bryan Cranston (Walt) and Aaron Paul (Jesse) on that final day of shooting, in very different states of mind: Paul was sad and sentimental ("This day is just horrible. Awful."), while Cranston was a jokester till the bitter end.

In fact, in the very last scene the Emmy-winning co-stars shot together, Cranston dropped his trademark tighty-whities and did a take with his bare butt to the camera. Speaking of Heisenberg's undergarments…

2. We almost didn't see Walt in his iconic tighty-whities.

"BB" creator Vince Gilligan recalls shooting the pilot episode, with Cranston in nothing but undies and an apron. It was a cold morning, and Gilligan remembers giving his star a chance to back out, asking him: "How do you feel about the underpants?"

Cranston responded: "What's the most embarrassing thing I could be dressed in?" When Gilligan replied "tighty-whitey underpants," Cranston said firmly: "That's what I'm going to wear. Because that's what's right for the character." And a classic TV image was born.

3. Aaron Paul is a super-intense actor… even at the table read.

The doc shows the "BB" cast and crew reuniting to shoot the final eight episodes and sitting down for a table read of the first of the eight, "Blood Money." We see Paul and Cranston reading an emotionally wrenching scene, and even though it's just a table read, Paul is fully invested; we even think we saw tears in his eyes. Do they give out Emmys for table reads? If so, Paul gets our vote.

Get an exclusive sneak peek at the "Breaking Bad" doc "No Half Measures" right here:

4. It took hours in the makeup chair to become Walter White.

We didn't realize this while watching the show, but Bryan Cranston didn't just shave his head to become Walter White; he also put on plenty of makeup to play a gaunt, cancer-stricken Walt in the final season. We see Cranston in the makeup chair getting latex skin applied to his face to add extra wrinkles and what he calls a "turkey neck." "What we're trying to do is age him and decay him," the star says.

[Photos: Go Behind the Scenes of 'Breaking Bad']

5. Bryan Cranston can take a punch.

During the filming of the pivotal scene at the end of "Blood Money," where Hank confronts Walt about being Heisenberg (aka the "Tread Lightly" scene), Cranston wore two hats: actor and director. (Cranston directed three episodes of "BB," including that one.)