I have so many memories of Mack that it's hard for me write something coherent (ok, I rarely write anything coherent, so harder than usual). I guess it starts back in 2005 around the Vegas bowl. Some may not remember but we had a really good center before Mack, Marvin Philip. Philip started every game in 2004 & 2005, finishing 2004 as an AP second team All-American and 2005 as an AP first team All-American, in addition to being named Cal's offensive MVP (for comparison's sake, Mack was only a third team AP All-American this year). Despite the prospect of losing our All-American center to graduation, I remember telling anyone who would listen (and not too many people will listen to you talk about back-up centers, especially in Vegas) about a redshirt freshman named Alex Mack who was apparently mauling people in practice. It's not too often that you can feel comfortable losing a first team All-American, but that's what Mack did.
I remember playing Tennessee at Memorial on NCAA Football 2007 and having Alex Mack pull and take out two guys to spring Forsett for a touchdown...and a few days later watching Mack take out THREE guys on almost an identical play (0:51 on the video) during the actual game. I remember Mack eliminating two WSU players to spring Forsett for a 40 yard TD against the Cougs (2:02 on the same video), our only win in 7 games and perhaps my favorite single play from the 07 season. I remember asking Mack after the USC game that year if he would be coming back in '08, and hoping that "I don't know, man" would become a yes. I remember watching Mack run around the sidelines after the Emerald Bowl, slapping hands and thanking everyone that could get close enough to him as he tried to extend his Cal career for another 15 minutes.
Ironically, Mack departs in a fasion similar to Philip - with a much talked about younger player ready to take his place. Chris Guarnero was a standout in practices as a redshirt freshman and played extremely well at left guard last year before going down for the year with a toe injury. He may not equal Mack in his Cal career (who will?) but judging by what we've seen so far (that's him sprining Best on the first play), Cal's in good shape yet again at center.