Kyle Williams couldn't bear to watch after fumbling away a punt at a pivotal moment in overtime of the NFC Championship Game on Sunday. (AP)

Here’s a news flash for you: we all make mistakes.

Last weekend I maintained confidently that the Australian Open was transpiring in Sydney. What a surprise that must have been to all those top tennis players gathered in Melbourne.

Among other mortals making mistakes last weekend were Billy Cundiff and Kyle Williams.

Billy Cundiff missed on a field goal attempt that would have tied the AFC Championship Game if he’d nailed the kick. His success would have brought Cundiff’s Ravens into overtime against the New England Patriots.

Kyle Williams of the San Francisco 49ers fumbled a couple of punts. Maybe if he hadn’t, the 49ers would have beaten the New York Giants. But maybe not. In the game’s aftermath, several of the 49ers maintained convincingly that they’d lost as a team.

Some didn’t buy that. One alleged fan tweeted re: Williams, as follows: “I hope you, your wife, and family die. You deserve it.” Another nitwit chimed in with a plea to the 49ers’ head coach. “Please give Kyle Williams the game ball,” he wrote. “And make sure it explodes when he gets in his car.”

Pro athletes are paid well, and some who watch them resent that the compensation doesn’t insure success.

Lots of fans bet on football games. Those people are inclined to take a team’s losses personally, since they result in personal losses. They shout things like “What are you doing to me?” at their TV sets.

Were the offending player to answer, he’d say, “Nothing.”

Billy Cundiff and Kyle Williams have lots of company. Players who’ve fumbled or dropped fly balls or otherwise bungled opportunities have often inspired idiotic excess from those who’ve watched them fail. The dismay hasn’t always been expressed in violent terms. Years ago, while speaking to a group of baseball fans, I mentioned former Boston pitcher Bob Stanley, whose pitch that Rich Gedman couldn’t catch became a link in the chain of events that enabled the Mets rather than the Red Sox to win the World Series in 1986. I said I liked Bob Stanley. A man in the front row gritted his teeth, turned red, shook his head, and told me that since that pitch, he had not purchased a single wrench or hammer or saw with the name “Stanley” on it.

I think he was serious.