Earlier this week I listened to "Every Book In The World", a radio play by Nick Warburton, about Sir Thomas Phillipps who had a maniacal obsession to own a copy of every book in the world. (Fwiw, this predated the idea of a "copyright"/"legal deposit" library by about a century.)

https://www.bbc.co.uk/programmes/b00771l3

Inevitably, he didn't succeed, but he did amass around 40,000 printed books and 60,000 manuscripts by the time he died in 1872.

Perhaps not surprisingly, disposing of his books after his death proved to be something of challenge -‑ incredibly, the final portion of the collection was only sold 134 years later, on 7 June 2006.

More info on Phillipps at https://en.wikipedia.org/wiki/Thomas_Phillipps

To paraphrase from the play, Phillipps's aim was not to actually read the books (not that he could ever have done so), it was simply to own them.

So, whenever, like me, you get mildly concerned about the number of books you own, and especially the number of books you own that you haven't (yet) read, comfort yourself with the fact that your situation could be a lot worse.

"How does the spring not run out almost immediately?" "We pull it back REALLY far."

https://xkcd.com/3244/