The book was probably printed in the early 90s when I was a child reading science fiction. I think it was largely about space sci-fi, but the one story that I remember clearly was called "Soft." It was about a future where some virus has infected the population that causes people's bones to suddenly and spontaneously go soft. A character is watching the news when the newscaster suddenly goes soft and they find the moment to be grotesquely hilarious.

I believe there was also a story about a person in an insane asylum who thought the whole world revolved around them. The reveal at the end was that he was being observed because he'd figured out the truth (that it was).