If you separate something like a meme virus from a stack and then use it, it isn't consumed and can be put back on the stack again.
This effectively means a limitless supply of them.
I took the stack from my stash, separated one and put the stack back in my stash. I then used the consumable which remained in my inventory so I could put it back in the stack in my stash.
I've mostly been playing with the Tech Adept so that's where I notice it.