Along with its overclockability, there was one peculiar feature of the "cacheless wonder," as the Celeron was then called, that blew everyone's mind: it performed almost as well on Quake benchmarks as the cache-endowed PII. What became evident in the ensuing round of newsgroup and BBS speculation over this phenomenon was that few people actually understood how caching works to improve performance.

http://arstechnica.com/paedia/c/caching/caching-1.html