If you can treat it as a game of endurance that you are willing to participate in then you will probably succeed. A lot of people on HN claim to have had multiple interviews over a couple of years, so failing to get hired is not going to ruin any future options with the same company.

A co-worker of mine recently was hired by Apple and I consider them rather unremarkable but also precocious. Other colleagues of mine that have worked at Google, Amazon, and Microsoft are very capable, excellent communicators, and very interested in pushing the edge of technology, but they are not super-human by any measure.