Cotton Bowl after the 1977 season. Texas was undefeated and ranked # 1, Earl Campbell won the Heisman Trophy, DT Brad Shearer won the Outland Trophy, Fred Akers won Coach of the Year. QB Randy McEachern started the season 5th string and considered switching to DB, went into the OU game 3rd string, and became the starter as the two guys ahead of him were injured and out for the season. We were heavily favored against Notre Dame, whose QB was Joe Montana, and I remember an article in Sports Illustrated proclaiming us one of the best teams ever in college football. Then we fumbled 3 times and threw 3 interceptions and the defense crumbled. We got beat 38-10 in the Cotton Bowl and it didn't seem that close watching it unfold. "The Agony of Defeat" for sure.
Cotton Bowl after the 1983 season. Texas was undefeated, with perhaps the best defense in Texas history, and ranked # 2, facing # 7 Georgia. Texas seemed in control most of the game but kept stalling in the red zone and settled for field goals. Made 3, missed a couple, but Georgia couldn't sustain anything against our defense. Score was 9-3 Texas in Q4 and Texas drove to within FG range again, and I figured 12-3 would no doubt be enough for the win. Instead we threw an INT deep in Georgia territory. Georgia had to punt but the returner muffed it (our 4th turnover of the game!), giving the Dawgs good field position and damned if they didn't punch it in and win 10-9. # 1 Nebraska would lose later that night so in theory this cost us a national championship.
Nothing else comes close to the empty feeling of watching those two games. Two opportunities to win National Championships gone in gut wrenching fashion.