Over the last few years, many have become obsessed with the concept of "Mortality Maths."

It's that feeling when you realize how old a particular point of pop culture is compared to how old it feels.

Case in point is brought to us by Twitter user Lev Parikian (@LevParikian) who is all too gleeful to make you feel old.

He set it up with a "warning" tweet.

Parikian's point involves George Orwell's seminal work 1984, which was published in 1949.

Twitter: @LevParikian

For those who can't see the image, it shows the publication date of the book on June 8^th, 1949.

On the other side of it is the day the tweet was posted, which was January 30^th, 2019.

And in between these two is an estimated date when the events in the book happened.

"We are now as far in the future from '1984' as [the year] 1984 was when '1984' was published."

Is anyone else starting to feel old?

This is the essence of mortality maths, a term coined by rock critic Peter Paphides. It's not universal to everyone, as different generations have different cultural milestones that are important to them.

For some, the idea that five years ago was when the last person Madonna name dropped in her song "Vogue" died is what will make you feel old. For others, it can be as simple as telling you it's been about ten years since Justin Bieber's first single was released.

And still, others may feel old knowing that starting last year, every single kid (in the legal sense of under 18) was born in the 21st century.

Other Twitter users decided to share their own mortality maths.

This isn't a new phenomenon. It's old enough that it's been shared, parodied, meme'd, and back to sincere again.

But it's the enduring feeling this leaves that makes it such a long lasting idea. As old as we may feel, mortality maths never gets old.