Us BYU fans sometimes come off as jilted and pessimistic when it comes to big games. Not sure how the collective CB feels, but I've heard many of my friends mention how BYU always chokes in big games. Here's the perspective from an LSU fan on the LSU board talking about BYU:

I think it's significant that they have either won or played closely to a lot of good physical teams in an "away" setting. The two texas blowouts show that they are more than capable of whipping a respectable opponent. Our team needs to be prepared for them to give us their very best shot. This reminds me of that 15-1 long shot at the race track who doesn't necessarily win horse of the year but finds a way to win a big race from time to time - BYU is definitely that type of horse! 

I think it's also interesting to note how winning a couple games against Texas has impacted BYU's national reputation.  I remember skimming opposing teams' boards (especially P5 teams) last year and a lot of fans bring up those Texas games and reference BYU as a giant killer.  If we can somehow manage to take down LSU, it'll continue to add fuel to the fire (in a good way)