Weird randomness has more of an influence on success in all fields than most of us like to think. Sometimes it depresses me that factors like timing and who you know make such a big difference, especially having been the sort of person who had been good at stuff like earning academic degrees, where the path to the goal is pretty clearly defined.
But another way to think of it is that you're just as likely to succeed as anyone else - the lightning is going to hit someone, it might be you. And even in academia once you get to career level stuff as opposed to just passing classes, it's the same deal. Who you work with, is your research topic fashionable, does the right department have an opening, does the best person to review your article have too much stuff piled on their desk to take it on... matters more than whether you are smarter than the next guy. There is no place where pure chance doesn't have a huge influence. But even chance can't help you unless you get off the couch, put on your #####, and get out there.
But this morning.... I have my ##### on but dang do I need a vacation.