It so often happens that I acquire a rarer parallel of a card before the simple yet somehow elusive base card. Really it's just a function of not busting product so needing to trade for the base cards whereas I seek out the rarer parallels and hits. I think it's safe to say that happens to most of us a lot of the time.
The latest occurrence of this trend centers around Ryan Getzlaf and his 2005-2006 UD SPx SPxcitement RC. The base version is numbered out of 999 and my PC of The Captain is still without it.