On the 10th day of May, the beautiful 10th day of May 13 Years Ago, Kate Gosselin was recovering from giving birth to six babies.

And you know what that means:

It means that we as a people have somehow survived being aware of the Gosselins for nearly a decade and a half.

Oh, it also means that yesterday was the 13th Birthday of the sextuplets, who became household names along with their parents on Jon & Kate Plus 8.

What a special day, huh?

Kate is now the mother of eight teenagers, which sounds like a special kind of hell, and she now has eight teenagers to withhold from Jon Gosselin.

And considering the challenges she's faced over the years, and will continue to face going forward, the woman is pretty happy about the whole thing.

In an uncharacteristically touching post she shared on her Instagram account yesterday, Kate wrote:

"HAPPY 13th BIRTHDAY, my precious Alexis, Hannah, Aaden, Collin, Leah and Joel!!"

"At this moment (7:51-7:53 am) 13 years ago, my life and heart were completed with your births!"

"I love you all and NO MATTER WHAT it requires of me, I will ALWAYS be there for you," she promised.

"I'll always be your biggest cheerleader, your role model by example, your shoulder to cry on, the hug and laugh you need, and your mommy and friend!"

Kate concluded: "I love you guys!"

"I got six times what I planned on, but I'd NEVER EVER go back! You're the final six pieces of my heart that I never knew I was looking for."

In another post just before their birthday, she shared a photo of a tiny diaper - the same kind they wore when they were born.

"Sitting in my room with the kids... thinking back to almost 13 years ago," she wrote in the caption.

"I pulled out this extra small preemie diaper from the NICU. I've kept in my bedside table drawer, wherever we moved ... to always remind me of how far we've come!"

She added that "the kids were awed" by this, which makes sense ... it's hard to believe that diaper would fit an actual human baby.

In the hashtags, she reminded us that when they were born, the sextuplets weighed between two and three pounds apiece.

Oh, how far they've come indeed.

But Kate wasn't the only one to share the celebratory spirit with us. Jon took this photo of the birthday cake he got for the kids:

"I can't believe my little kids will be 13 tomorrow!!!" he wrote in the caption to his own post, also shared yesterday.

He even took things a step further, giving a quick interview to E! News about the newly-minted teens' special day.

It turns out he got to spend actual time with a bunch of them, which is no guarantee given his relationship with Kate.

Jon explained that he was able to celebrate the kids' birthday on Monday, and that "I had four of them: Hannah, Lean, Joel and Aaden."

"I cooked burgers and hot dogs on the grill and we did presents and played football in the backyard," he said. "After that, we did cake and ice cream."

"It was good."

When asked how it feels to be the parent of eight teenagers at the same time, he said "It's only been a couple of hours, so we'll see."

"It's going to be interesting!"

Yeah, Jon. We bet it will be.