So, having started the thread..
For a long, long time, I worked with the Big Bag of Dice I had collected in the years since I started back in junior high school. Back then, I had come across a rather nice piece of suede, and (very inexpertly, but very solidly) stitched it into a drawstring bag. One sunny summer day, playing outside on a friend's patio, said friend used a magnifying glass to burn my initials in the bag while I wasn't looking. While not skilled or artful, it was still a great gesture, so it has some hefty sentiment attached to it. None of the dice within are matched sets. I just added random dice to it over time. I eventually stopped buying new dice after a while, because I always had enough in the bag, which I still have, sitting at my hand as I type....
Then, a couple of years ago, I started playing D&D with a group at work, and I didn't want to lug around all my dice, so I got a small bag and a couple of sets that I could leave at my desk.
Then, after I inspired him by running Lost Mine of Phandelver for him and his daughter, a friend of mine started running a game, and I repurposed those sets, and was given a set as a gift...
Then covid hit, and I got invited to play in another game online, in which the GM is fine with us rolling physical dice and telling him the results. I bought my wife some dice for that as a gift, as the ones she had weren't thematically appropriate for her character, and while I was getting her some, I got some for myself...
And somewhere along there, I became a guy who runs games out of the old dice bag, but plays them with purpose-bought sets, which is odd, but the way it is...