Absolutely this. My father was an immigrant from an eastern block country. Just a regular family, his father was a salesman, his mother a secretary. Father was

Absolutely this. My father was an immigrant from an eastern block country. Just a regular family, his father was a salesman, his mother a secretary. Father was valedictorian of his high school, speaks 6 languages, ect. Scraped together enough money to study at a British grad school, finished in 1 year as valedictorian. Then he immigrated to America. So someone looking at his math achievements might think wow, they really teach those soviet immigrants math well! But it was more like the best of the best immigrate while someone more average like me would be stuck in the old country.