I'm afraid to count the pieces of audio gear, records, guitars, etc. I've bought from older gents who no longer had a use or the interest in keeping it around. I heard many reasons - downsizing and moving being the most prominent but also to fund trips, pay bills, tuition or weddings for grandkids or they just needed the cash.
One of my most memorable bitter/sweet buys came about when I responded to an ad in the paper and met a fella in his mid '60's selling 3 nice guitars - a '72 Les Paul Custom, a '71 ES-175 and a '70 Martin D-28, all in great shape and well-cared for. As I checked them out, he told me that he hadn't been able to play them for years as he had arthritis and it hurt to even hold the guitars but he had held onto them because he met his wife while playing and through the years, she had always enjoyed singing along as he strummed. Sadly, she had passed a few months before and he had realized that the guitars were just reminding him that he couldn't play and had no one to play for so they had to go. He said his kids had no interest and no idea of their value so he took it upon himself, but man!... I could tell this was not easy for him as he was letting go of a lot more than just 3 guitars. It took me about 15 minutes to decide on the guitars but we spent a couple of hours talking, mainly I think, to give him some assurance that his guitars were going to a good home but also so he could tell his story and pass it along.
I've made many deals with folks for whom the switch just went 'off' and they no longer wanted the gear taking up space and somewhere in the back of my head, that's kinda how I hope it goes down with me...on my terms. But the ones that stick with me are the fellas who are still interested and loving their hobby but are no longer able or capable of continuing. In my mind, that's gotta be some level of hell.