Anedoctal example, but I graduated with a decent mark from the top CS department in my country (106/110) as an UG, I couldn't even apply for a masters in top universities in the UK (let alone US) since their requirements are skewed towards not accepting people from my country (if you came from the UK you needed a 2:1, which if I remember correctly is around 70%, if you came from my country you needed 109/110, which is over 99%. Scores for other EU countries like Spain and France were converted to their 70%). This led me to going into a masters in my country, which will most likely hinder me from getting a PhD in any top institution in the EU just because of the country I was born in, even though some of the professors in my current masters degree course are top researchers in their fields. So yes, I feel like where you go to school earlier in life greatly influences where you will end up in the future; and even more so, where you were born influences your chances of making it anywhere in life. This is not to say that I am some unrecognised genius, I feel like I am a "median" CS student with a poor math background to booth; but at the same time I absolutely feel like a lot of talent will go unrecognised and won't have the same chances in life others have just because they happened to be born in a country rather than another (even more so after having studied in the UK for a year and having met people who went on to work for top companies when they clearly were subpar compared to people studying in my own country)