3. It Nearly Brings Everything Full Circle
Since 2005, a big part of the Doctor Who story has been missing. Great chunks of the Doctor's past had been detached like melting icebergs. What happened to the Eighth Doctor? What kind of life did he lead? How did he die? Now pretty much all of those questions have been answered because, apart from bringing back the Eighth Doctor and giving Paul McGann more screentime, The Night Of The Doctor is hugely significant by finally showing the Doctor's eighth Regeneration. This Regeneration has been eight years in the making. And although we couldn't see it in full because a full length Regeneration featuring a young John Hurt just wasn't feasible, it's still one of the last missing pieces of Doctor Who falling into place. All we need now is for the War Doctor to Regenerate into the Ninth Doctor (assuming that Steven Moffat doesn't have something else up his sleeve), and the circle will finally be complete with all of the Doctors lives and deaths so far being shown onscreen.