Back in April, David Letterman announced that he was retiring as host of ‘The Late Show.’ Almost immediately, the Internet flooded with speculative lists on Letterman’s possible replacement -- which eventually turned out to be Stephen Colbert – and retrospectives on Letterman’s career, with almost all of them focusing on Letterman’s run on NBC’s ‘Late Night’ (I am guilty of this). As we draw closer and closer to Letterman’s last show, there will be an uptick in additional retrospectives (I promise I will be guilty of that, too) as Letterman’s show surely transforms into a star-spectacled rumination as we all say goodbye. But what’s interesting about ‘The Late Show’ is what’s happening right now.

To be fair, there really hadn’t been a lot to talk about at the time of Letterman’s announcement in regard to ‘Late Show with David Letterman,’ so writing about Letterman’s most influential era makes sense. Shortly before his announcement, even Letterman had joked that he didn’t put the time into the show that he used to, which made his retirement not that surprising to anyone who had been paying attention. Plus, the late night landscape had changed so drastically: Jimmy Fallon had just reinvigorated a stagnate ‘Tonight Show,’ and the reality was Letterman wasn’t going to spend his time making Internet-friendly videos in an effort to keep up with his competition. (Though, as we saw with Letterman’s tribute to Robin Williams, Letterman’s now unique sincerity can still go viral.) Letterman had a deep-seated drive to beat Jay Leno; I suspect Letterman doesn’t care much about Jimmy Fallon one way or another.

Like a lot of people, I hadn’t been watching Letterman much at the time of his retirement announcement. I’d tune in here or there, but it was obvious that Letterman’s interest level with the show wasn’t high. He seemed distracted at times, often phoning in interviews with the guests he didn’t care about. This was the most disappointing aspect about Letterman in recent years, because when Letterman cares, he’s one of the best interviewers on television. The problem was that it was obvious that Letterman had stopped caring.

Letterman doesn’t look like a guy who wants to retire anymore. He finally looks happy.

It was the night that Jimmy Fallon preformed a combined somersault with Halle Berry in a feature called ‘This is How We Roll.’ I admire the way Fallon has turned ‘The Tonight Show’ into a refitted variety show for the 21st century. Fallon cracked the code on how to somehow make the classic talk show format relevant again. But, having said that, it was this particular segment -- as I watched Fallon and Berry roll across the stage -- that made me think to myself, “Man, there has to be something else going on.”

Since then, I’ve been consistently watching Letterman again (it’s not like Fallon’s show is leaving anytime soon) and I discovered something remarkable about post-retirement announcement Dave: He seems to be having the time of his life.

The thing is, we’ve all been there. We’ve all had those jobs that made us miserable, but the something changes once two weeks notice is given. All of a sudden, that job seems fun again. And like that, all of the aspects that made us miserable are gone. Why am I leaving again? This is David Letterman right now.

A few weeks ago, Letterman interviewed assorted cast members from the movie ‘Guardians of the Galaxy,’ and Letterman was acting like a kid who had just seen ‘Star Wars’ for the first time. It was obvious that Letterman really liked ‘Guardians of the Galaxy’ and he didn’t even attempt to hide the joy from his face.

We live in an era of planned spontaneity. MTV’s VMA’s are a great example of this, where we’re told that anything might happen, even though what we see is pretty much exactly what was supposed to happen. The streaker at the 1974 Academy Awards was a true spontaneous moment, followed by David Niven’s now spontaneous famous line, “Isn’t it fascinating that the only laugh that man will ever get in his life is by stripping off and showing his shortcomings.”

Of course, this was a long time ago. (For the record, I was not born yet when this happened; so this isn’t some ill-placed nostalgia.) But we still remember it because it was real. Now nothing is real and 40 years from now we will probably remember very little from this era.

But watching a refreshed Letterman somehow does feel real. Here’s a guy just enjoying his last few months on the job – with a renewed sense of purpose after vanquishing his rival, Leno. Letterman watched as Leno was yanked off the air, replaced with Jimmy Fallon – a public comeuppance after Leno did the same thing to Conan O’Brien. Perhaps this brought peace to Letterman’s mind about losing ‘The Tonight Show’ two decades before. Perhaps Letterman thought to himself, I bet NBC would have done the same thing to me. Instead, Letterman decided his own fate and was surely involved with the picking of his successor. No one forced Letterman out. Letterman got what so few people get in show business: he got to leave on his own terms. Leno won the ratings war, but Letterman won the relevancy war; and the latter is all that really matters.

I bet there are days that Letterman reconsiders his decision. He probably thinks of his hero Carson, and Carson’s relative obscurity after leaving ‘The Tonight Show.’ On his final show, Carson hinted at other projects, but that never really happened. Letterman’s situation is different, he has a wife and a young child and his racing team. Letterman even joked the other night that he wasn’t retiring and didn’t even bother to tell explain to the audience that it was a joke. Then, a few nights later, he was out on the street with Serena Williams, shattering storefront glass with tennis balls on the streets of Manhattan. Letterman doesn’t look like a guy who wants to retire anymore. He finally looks happy. He finally looks triumphant. He knows he has finally won.

Mike Ryan has written for The Huffington Post, Wired, Vanity Fair and GQ. He is the senior editor of ScreenCrush. You can contact him directly on Twitter.