My 10,000th Day of Life

Today, I am exactly 27 years, 4 months & 19 days old. That might seem like a strange feat to record:

5/3/19 - the day when I was 27.38 years old.

However, if my mathematics is right, today I am exactly 10,000 days old. As I stand here before you (well, sit, I sit at my desk to type), the sun has passed over me exactly 10,000 times.
That is, if my maths is right, anyway... the Word of the Day is: 'THOUSAND'

Thousand /thowzənd/ n. 1. A cardinal number, ten times one hundred. (10 × 100). 2. A symbol for this number, as 1000 or M. 3. A great number or amount: A thousand pardons. 4. One in a Thousand, Very good; outstanding. ♦det. 5. Amounting to one thousand in number. ♦pron. 6. A thousand people or things: A thousand came to the match.

I was born on October 18, 1991. On October 19th,  1991, I was one day old, but on October 18th 1992, I was 365 days old - well, actually, I was 366 days old, since it was a leap year, but I'll deal with that later.
So on that basis, we do our mathematics.
10,000 ÷ 365 is 27.397..., so I knew it was after my 27th Birthday.
So, I just did 27 × 365, and since it was a leap year in 1992, 1996, 2000, 2004, 2008, 2012 & 2016, I added seven (+7) to the result, and we get = 9,862.
Now, we just need those last 138 days. So, I counted forward from there.
There were thirteen more days in October, so 9,862 + 13 = 9,875
Thirty days in November 2019, so 9,875 + 30 = 9,905
Thirty-one days in December 2019, so 9,905 + 31 = 9,936
Thirty-one days in January 2019, so 9,936 + 31 = 9,967
Twenty-eight days in February 2019, so 9,967 + 28 = 9,995
Now, we're so close, less than 30, so I just add the last five days
Five more days into March 2019, so 9,995 + 5 = 10,000 Days

So, my 10,000th day is today, Tuesday 5th of March, 2019.

Now, at first glance, this might seem completely arbitrary. It's just ten-thousand days, big whoop, who cares? But, if you ask me, it's an eye-opening look at both how long and how short our lives are. See, the reason why I'm focusing on this day is because it is the only milestone measured in days, in order of magnitude, that we can truly appreciate. If you're not sure what I mean, allow me to explain.
1st Day? Well, you're one day old, barely even sapient at that point.
10th Day? Nine more days of experience isn't much better than that.
100th Day? That's just three or four months, we can't even speak.
1,000th Day? Things speed up now, almost 3 years old, you can speak, but you're still too young to even understand the concept of milestones - although you're out of nappies (probably), but very few children at this age can count well enough to know how old they are.

And, you can't go past 10,000 days...

100,000th Day? This would make you over 270 years old. Our understanding of aging is that the reason why we all get old is because the parts we are built from inevitably break down. We have the ability to heal, and regenerate cells, but this regeneration and rejuvenation is imperfect. The reason why we eventually "get old" is because what manages this regeneration is our DNA, but the deterioration of telomeres at the ends of our DNA strands means that our bodies gradually get worse and worse at repairing themselves. It's a basic law of entropy, everything eventually wears out, breaks down, and disintegrates. And, according to the most recent findings, the average shelflife of your telomeres is about 120 years, meaning that after that, you lose the ability to heal and your cells inevitably break down.
So, for a human being to live for 100,000 days would be nothing short of a miracle.

And knowing this, it brings this day into perspective. I am 10,000 days old. I will only be this old for exactly 24 hours, and then it will pass. Tomorrow, I will be 10,0001 days old, today will fall behind me, and I will move on with my life.
What's odd is, even though this day is only significant to me is because I will die (before I reach 100,000 days, at least) and so it is a fleeting moment to consider, I'm not sad or even melancholy. Perhaps I'm too young for that, and need a midlife crisis before I start despairing.
But, today, I just feel good that I've gotten this far. Today, I spent the day writing, watching Fact Fiend on YouTube and reading summaries for old children's horror stories.

So, if you're younger than 27 - or have turned 27 quite recently - why not figure out when your 10,000th Day is?
Or, if you're older, are there any other unusual milestones that we tend to miss? Maybe your millionth second? Basic maths tells me that you'd be about 31 years old at the time, although you wouldn't have long to celebrate... But, maybe there are others which I haven't considered.
Speaking of milestones, this post is actually my 299th, so the next milestone that I'm going to pass is my 300th post. I'm not sure what I'm going to do for it, if anything at all... but, I have more milestones fast-approaching.
I considered writing a post so that my 300th post and 10,000th day would coincide, but this day snuck up on me way to fast for me to do that.

I'm the Absurd Word Nerd, and until next time... well, yeah, I'm gonna be working on the 300th post. In the meantime, I hope you're having a great day. And, if you like, feel free to talk about your own specific or unusual milestones in the comments below.