From the apparently just published, Coders at Work (Apress, 2009), Brad Fitzpatrick Talks About Programming:
In practice, nothing works. There are all these beautiful abstractions that are backed by shit. The implementations of libraries that look like they could be beautiful are shit. And so if you’re the one responsible for the cost of buying servers, or reliability – if you’re on call for pages – it helps to actually know what’s going on under the covers and not trust everyone else’s library, and code, and interfaces. (…)
They should have titled the book, “In Practice, Nothing Works”. Anyway, you can grab the — ick — PDF ebook for $20 on Apress.