I have a bunch of old coffee mugs from TV shows, art museums, even an apartment complex I used to live. In once sense these aren’t replaceable. If I ever break my Mozilla Coffee mug or the “I’m in the middle of fifteen things, all of them annoying” quote from Cmdr. Ivanova, or if I lose the “Venti Schmenti” travel mug from Diedrich’s (a coffee chain that has since been absorbed by Starbucks), that’s it — I can’t get another one.
But I have plenty of other coffee mugs, and there’s no shortage of mugs I could buy to replace them if I had to.
As memorabilia, they’re irreplaceable. Functionally, they’re almost expendable.
It’s interesting to think that they’re both, depending on how you’re looking at them.