In the first ever episode, Kourtney smiled for virtually the entire duration.
And her playful side was clear to see. In the first episode, she and Kris went wine tasting, but quickly got bored.
And proceeded to get absolutely shitfaced.
She spent most of the first three seasons play-fighting with Khloé.
And coming out with amazing one-liners, usually at the expense of Kim.
Especially in moments like this, where her laughter was just contagious.
And when she split up with Scott at the end of Season 3, and headed to Miami to film a spin-off show with Khloé, she was at her absolute fun-loving peak.
She did things like chant this at Kim when she refused to drink alcohol.
Yelled this at guys on the beach.
Was still full of one-liners.
And allowed Khloé to do things like this to her.
But at the end of the season, she ended up hooking up with Scott and fell pregnant with Mason, and the pair got back together. But Scott's behaviour has been spiralling out of control ever since.
As time went on, Kourtney became more reclusive, unenthusiastic, and generally unhappy.
Most of her storylines became centred around being upset and disappointed by Scott, and this fed into her general mood.
And after Scott's drinking got really out of control, she even separated from him for a while.
But although they got back together, the negativity still remained – especially during conversations like this, just months after Kourtney gave birth the second time.
Of course, Kourtney played her part in the breakdown of their relationship, refusing to sleep in the same bed as Scott and not making time for them as a couple – something Kim was very vocal in pointing out.
But when Scott's parents both died within three months of each other, he hit an all-time low. It was at this point that their relationship truly began to crumble – especially when Kourtney announced she was pregnant for a third time.
Scott's reaction couldn't have been worse.
And it was sad to see Kourtney feeling so anxious about Scott's reaction that she couldn't ever really be excited about the pregnancy.
This continued into the spin-off season of Kourtney and Khloé Take the Hamptons, which was filmed throughout her pregnancy. Despite Kourtney trying to help Scott, his partying became out of control.
During one conversation, Kourtney told Scott she didn't want him to use club appearances as "an excuse to get drunk". This brutal conversation then ensued.
But when Kourtney went out of town, Scott got so drunk he ended up hospitalised, and spent a brief spell in rehab.
And during yet another club appearance after he left rehab, Kourtney rang Kim for advice. During the course of their conversation, Kourtney made her strongest hint yet that she was seriously contemplating her future with Scott.
And she made it clear how lonely she felt.
And Kim suggested that perhaps at this stage, Kourtney was running out of options.
And as Kourtney's due date grew ever nearer, the lack of support from Scott and the disconnect between the couple was clearer than ever.
When Kourtney found out she would probably be delivering early, she questioned whether Scott, who had numerous personal appearances booked in, would even be there.
His response here wasn't great either.
And after finding out all her family, apart from Kris Jenner, were going to be out of town around her due date, she broached the subject again.
And this time it really was heartbreaking.
And when Scott went on another bender just months after baby Reign was born, Kourtney decided she had to do that "something drastic" Kim mentioned – and broke up with him.
And these scenes were devastating, too – especially given that Kourtney very rarely cries on camera.
And since then, it's as though Kourtney has become a different person. Or, more accurately, has gone back to being the happy, playful Kourtney from years ago.
First of all, that smile is back.
I mean, have you ever seen a more genuine, glowing facial expression than this?
And we also have to acknowledge how goddamn incredible she looks right now. And this isn't some kind of intentional ~revenge body~ – she began working out to relieve the anxiety that began crippling her when Scott disappeared on his bender.
And as a result she now looks like this. 🔥 🔥 🔥 🔥
I just can't.
In fact, she's so confident she even posed for a nude photo shoot during the most recent season of KUWTK.
And look who shared a photo of her. Oh yes, that's Lord "do it the healthy way but do it faster" Disick.
Obviously Kourtney didn't even acknowledge the comment. 💁
It's also interesting that feeling stressed about Scott all the time physically wore her down, and changed her appearance.
But now she's single, she looks almost identical to how she did the last time she was single, after splitting from Scott in 2009.
This scene was from that period, and despite it now being seven years later, she looks exactly as she does now.
While we're on the subject, we also need to acknowledge how on point her style is right now too.
But it's not just about how she looks. In the latest season of KUWTK it was abundantly clear that Kourtney's personality has changed too – and she's back to her old self, delivering one-liners like this.
Her play-fighting with Khloé has resumed.
As has her playful nature in general – including taking great pleasure in torturing Kris Jenner.
Or just ignoring her completely to take happy selfies.
And her family have noticed the change too, with Kris noticing the difference in her appearance.