With the right outlook, it was the single most profitable piece of luck one could have to balance all the other not so great things from communism.
A lot of university students in Moscow, Kyiv, St. Petersburg or any bigger Soviet city weren't actually born there. If you were from another city the university will give you dorm room if you pass the entry exams.
In case of Pajitnov luck is more about getting a job at Academy of Sciences, but probably it has something to do with his talents.
Education-wise, YES, the USSR was a meritocracy, way more so than the United States. My father was born in a God-forsaken Ukrainian village, and he studied in then Leningrad.
After you graduate, of course, it's different. It requires significant maneuvering in the political system and ample butt-licking to get anywhere serious.