We all invest too much emotionally into this fucking sport, :lol.
Losing seasons are hardly tough to bear, as are losing multiple seasons over and again. You come to expect it, and your emotional investment is not nearly as high. I've gone through it with the Broncos from time to time, with the Rockies more often then not, and especially with the Nuggets.
When your team starts to rise though, the investment rises with them. When you do reach that Superbowl, it's at a peak. Either you blow that emotional load with a victory, or go limp with a loss. Losing big, while winning is tougher then losing while losing if that makes sense.
That doesn't mean that when your team is bad you don't watch (or in Kas' case while they are okay), it just means that your expectations are grounded. You can't get as hyped up over them.