When "Doctor Who" reached its landmark fiftieth anniversary in 2013, fans worldwide were thrilled (simultaneously!) to see David Tennant and Matt Smith onscreen together for the first time ever. It was a nerd's dream come true, but when all eleven Doctors later converged on Gallifrey, many of those same nerds were once again sadly reminded of a critical absence -- the Ninth Doctor, Christopher Eccleston, who was shown only in stock footage. He didn't even show when the War Doctor (John Hurt) regenerated, which was especially shocking given that even Tom Baker found the damn time to make a cameo.

Of course it shouldn't have come as a huge surprise that Eccleston didn't show up -- his short tenure was reportedly not easy, and the actor has spoken a bit about his negative feelings towards the "Who" higher-ups since his departure.

However, that moment in "Day" also reminded fans -- well, me, at least -- of how important Eccleston's Ninth Doctor is to the show's legacy, even if he didn't have David Tennant's swagger, Matt Smith's infectious alien charm, or Peter Capaldi's gravity (mixed with a killer sense of humor).

Here's what he did have, however, which was pretty f--king fantastic:

He had great, non-romantic chemistry with his companion.

Everyone stans over the chemistry between Piper's Rose and Tennant's Doctor -- which I totally get, but one should not discount that it was Nine and Rose who first made us fall in love with nu-"Who."

Much like Peter Capaldi with Jenna Coleman's Clara, Nine started out treating Rose like a funny little alien, and eventually grew to respect her as a crucial member of his team. (Unlike Clara and Twelve, however, he was always relatively nice to her.) Between his heartbreaking efforts to understand her while also saving the world in "Father's Day" to their mutual thrill in saving everybody in "The Empty Child"/"The Doctor Dances," it's always nice to revisit Series 1 and remember what "Who" was like before romance entered the equation.

He was fun...

The Ninth Doctor thought everything in life was fantastic. A crucial element of "Who" is the Doctor's strange love for the human race even when it enrages him, and watching Nine react with bemusement whenever the "stupid apes" came up with something new never stopped being hilarious -- well, probably because it wasn't given the time to.

... But he also could play "Tortured Time Lord" when necessary.

"Dalek" is still the best usage of the Daleks in nu-"Who" history, and that's largely due to Eccleston's incredible performance when he gave the audience (and Rose) the biggest bomb-drop in Whovian history -- he was the last of his kind, and had murdered all of his own kind due to the never ending wrath of the Daleks in the Time War.

It was a thrilling way to kick off the new series, with the Doctor having a more dark and troubled soul than ever before. The three Doctors that followed him somehow became even more dark, but still -- Eccleston pulled off the difficult combination of a man with the weight of the world on his shoulders and a free spirit in love with adventure seemingly effortlessly.

He was believably alien.

I say this knowing that I will soon be murdered: Tennant and Smith are, as Nine would say, fantastic, but if you introduced a newbie to one of their episodes, chances are said newbie could easily be convinced that they were playing humans. Eccleston was just such a weirdo, with his manic energy and strange physical presence constantly reminding you that this creature was not of this earth.

He tried something different.

Say what you will about his long leather jacket, his black trousers, and his frocks, at least Eccleston tried something entirely new with his Doctor's look and demeanor. This was crucial as "Who" moved on from that last TV movie to its brand new series -- Eccleston needed to differentiate himself from a series that had grown old and silly, and his efforts 100 percent paid off.

True, we quickly moved back to nerdy-looking Doctors who loved accessorizing, but what made Eccleston so different is at least part of what made series one so thrilling. We felt like we were watching something completely different from what we'd seen in decades past, and without this, who knows if "Who" would even have moved on to a series two.

Jackie Tyler liked him.

The woman had impeccable taste. Her opinion shall always be trusted.

"Just this once, everybody lives."

I mean, need I say more? The joy and pain that comes with being the Doctor has never been more apparent than in this beautiful, all-to-brief moment.