That shit is more real than people think. My mom, may God rest her soul, went thru a period of hoarding after all of her children left the house. It was like she went thru an "empty nest" syndrome and thought that since her kids were grown and gone, she should fill the house up with a bunch of crap. We would go in and help her clean it all up only for it to be done again. When she passed away from heart disease we went in to her place expecting it to look like hell, and it did! It took us 3 days to clean out all the crap she had in it. I believe it's a psychiatric issue.
My grandma is going thru that stage now. She's been a neat freak all of her life but she's in her 80's now and doesn't keep her place near as clean. If you all see signs of hoarding please try your best to intervene. It's not healthy and there may be a mental issue going on.