I wouldn't call tinkering with Pascal and C while in High School necessarily a long time. He had one CS class at Stanford, in which he didn't really excel (sour

I wouldn't call tinkering with Pascal and C while in High School necessarily a long time. He had one CS class at Stanford, in which he didn't really excel (source: his Quora answers compiled here http://www.forbes.com/sites/limyunghui/2012/04/09/inspiring-insights-by-instagram-ceo-kevin-systrom-the-man-who-built-a-1-billion-startup/4/ http://www.forbes.com/sites/limyunghui/2012/04/09/inspiring-... and foundation podcast by Kevin Rose).