You have the Padres/Mariners rivalry shirt. You have the box set of Padres/Mariners DVDs. You remember where you were for the famous Luebke/Fister duel just as vividly as you remember the famous Mesa Meltdown of 1999. You're a true fan.
And now baseball wants to take it all away from you. Rather, half of it. From ESPN New York:
With the Houston Astros moving to the American League West next season and the leagues becoming balanced at 15 teams apiece, natural rivals throughout baseball no longer will be guaranteed six games a season and home-and-home series, the sources said.
Instead of six Marlins/Rays and Twins/Brewers games, there's a chance that we'll only get three. But there are other, more publicized rivalries that will be nixed, too. That might be the biggest change from the Astros moving to the AL, other than the whole "Whoa. The Astros are in the American League now?" thing.