1.   First, Jerry Seinfeld announced that his self-titled sitcom will end its wildly successful nine-year run in May.

2.   It had to end end because all sitcoms must end, sooner or later, mostly sooner.

3.   NBC agreed to it largely because it feared losing its Thursday-night juggernaut entirely after Seinfeld announced his sitcom was ending its run.

4.   When a popular sitcom about a loving couple ends the season with a gut-wrenching fight, viewers get mad . . . really mad.