The final season of the biggest show in the world premieres 9 p.m. Sunday on HBO.

HBO’s “Game of Thrones” begins its final season Sunday, an abbreviated run of six episodes that’s likely to claim the lives of nearly every character fans hold dear.

But when it’s all said and done, the biggest loss in a post-“Thrones’” world might be television viewing as we know – or rather, knew – it.

When the series, based on the books by George R.R. Martin, began in April 2011, it wasn't the monumental hit it would become. The first episode drew a 2.2 million viewers, respectable considering watching required an HBO subscription – and mind you, this was before borrowing your friend’s HBO Go password was all the rage.

The show took the old-fashioned route to building a viewership beyond its loyalist book fans by serving up jaw-dropping twists, political power grabs and salacious misdeeds – all in the name of laying claim to the Iron Throne.

Over time, “Game of Thrones” became the show to watch with friends, theorize about with coworkers, read recaps about online and, if you dared, venture into the depths of Reddit boards to engage in a larger community of obsession. In time, it became the biggest television show in years, evidenced by the 12 million people who tuned into the season seven finale live. All told, each episode is now watched by 25 million people over streaming sites and HBO replays.

In no uncertain terms, there will never be another show like “Game of Thrones” simply because it might be the last show we, as a pop-culture-loving country and world, watch together.

As the sands of the television industry continue to shift with streaming services dominating and broadcast and cable struggling to keep up, there’s an increasing erosion of the idea of “appointment TV.”

Gone are the days of sitting down at 8 p.m. and watching “Friends" or gathering around the TV to watch "Survivor" or "American Idol" – even though those two are still at it. Today, our collective viewing experiences are reserved for sporting events and award shows, live events that lose their shine if not consumed in the moment.

When I was a teenager, I remember the soul-crushing dilemma of having to choose between the series finale of “Will and Grace” and the third season finale of “The O.C.,” the latter of which promised the death of a major character. Even stakes like that don’t hold the power to draw in viewers in droves today.

This isn’t because television has eroded in quality and is no longer worthy of our immediate attention. In fact, ask any number of TV critics and they’ll tell you television has rarely ever been better.

But with the gluttony of options for watching content, sitting down in front of your TV sets between one hour and the next is not a requirement.

Efforts have been made to curb that change in behavior. Appointment television adapted, in some ways, to the age of social media consumption by branding watercooler shows like “Grey’s Anatomy” and “Scandal” as must-watch-live series that you could tweet along with and risked being spoiled if you missed out.

Some shows still have shades of live retention, such as "This Is Us" and the early years of "Empire." But those have faded with time.

What makes “Game of Thrones” the exception is its perforation of our culture and its towering scale, traits typically reserved for movies. It unfurled week to week, not dropped all at once on Netflix to consume at your leisure.

It was both the future of television and a rare fragment of a past era of it. We are presented with so many shows every week now that most fade in the conversation within days. But “Games of Thrones” established itself early on as a television event – when that meant something. It demanded to be watched live without actually having to demand it. It's narrative, its craft and its dragons did that job for it.

It united us across age, gender, race and political divides – something I think new shows would be hard-pressed to do in today's climate.

It redefined television, gave hope that ratings and collective viewership could still be attainable, and every network and service is desperately looking to recapture that as it fades to black – HBO included.

So, as “Game of Thrones'” characters prepare to make their final play for the throne, don’t just let the chaos and budget-breaking action wash over you. Absorb the communal experience of its dominance in the zeitgeist.

It will never be like this again.

Reporter Hunter Ingram can be reached at Hunter.Ingram@StarNewsOnline.com. Hunter is a member of the Television Critics Association.