Setting personal records is usually an optimal experience. Being a high level athlete is a great feeling. Those personal best times can be a huge carrot to chase in training and fuel the motivation fire. When you set the bar so high it can be painful too. Some stars are hard to catch again.
Despite running a smokin' 2:47 (that is a 6:22 pace average. 1 mile at that pace would kill me let alone 26.2 miles) Steve missed his PB at the St George marathon today... It can be gnarly when you have set the bar so high for yourself.