It's when you go in the loft and find tea chests with stuff in them from when you moved in.
Or worse still, from the previous move to that one!
I have a book case full of books i rescued from my dad' s house after he died. All good books though a bit heavy, history arts and culture type things.
It's 3 rows high and about 5 feet long. He died in 1998 and i have yet to read more than one or two of them. Wifey keeps buying me tons and i read those all the time.
Now she wants me to "go through your dad's and throw most of them out, you're never going to read them all." Well what i kept was about 1/4 of what my dad had and he'd read all of them!
Must run in the bloody family.
But best of luck with the sort out, not fun at all I'd imagine.