I grew up in Soviet Union and have a pretty solid idea what you could and what you could not say, but thanks for trivia.
A life anecdote: in mid 1980s my classmate shot the Lenin portrait in the classroom through a straw. His parents were called in and reprimanded. In 1950s they'd been in real trouble; in 1937 they would have been arrested, tortured and likely killed. In 1989 nobody would have cared.
https://en.wikipedia.org/wiki/Novocherkassk_massacre