You have to explain to younger kids what mix CDs were.
Just like when we had no idea what 8-track tapes were, there will be a terrible moment when you meet some little kid who has no idea what a CD is. They won't know what it's like to download songs off Limewire, carefully order them into a perfect playlist, burn the playlist onto a CD, and then put said CD into your Discman or boombox and enjoy.
And so you will have to explain this to them and while you are explaining and getting all caught up in nostalgia, they'll probably be snapchatting their friends like, "OMG can she not?" And when you're all done with your trip down memory lane, they will say something like, "That sounds like a LOT of work," and a little part of you will die inside. And then you will probably fall and break your hip.