It was often found that only stupid people do not find things funny. It appears as if only smart people are the ones who get jokes. That if one does not have a sense of humour or does not get a joke it shows how ignorant they are, and that they are of a low intelligence. One could also say that serious people have no soul, and possibly could be assholes, socialists, Liberal Terrorists, or possibly a member of IWETHEY, or some of each or all.
Seriousitis is a terminal illness that affects the brain and damages the sense of humour part of the brain. People who suffer from this illness take everything seriously, and consider jokes to be nonsense or lies and not funny at all. They end up not getting jokes, and get very angry at the people who wrote or told the jokes. A tell-tale symptom of this illness is that the person suffering from it cannot take a joke. In fact they find that this whole article, and all of Uncyclopedia are to be taken seriously, and that it is all nonsense and lies.
There are three types of seriousts, weak seriousts and strong seriousts.
Strong seriousts take everything seriously, and believe everything they are told as serious and thus true. They believe that If it is on the Internet it must be true and they even believe the fiction they read as true. If you tell them a joke like "Hey, your refridgerator is running." they will likely reply with "It is? I'd better go catch it!" because they believed what you said was true. They often fall victims of scams and will believe anything they are told, like supply-side economics actualy works and that George W. Bush is a cabbage.
Weak seriousts mostly believe that everything is true unless there is proof saying otherwise. You can try the "Hey, your refridgerator is running." joke on them, and they will reply by going home, checking it out, and coming back and saying "I checked, and it was not running, you lied to me!" They are the ones who feel that Uncyclopedia is full of lies because they see the fiction on Wikipedia and think that it is factual, and thus conflicts with the true statements in Uncyclopedia which proves to them that Uncyclopedia is full of lies, and the article writers are the lying liars who lied to them.
If a weak serioust finds a Wiki article that they think is a lie they will blank it. If it was a post on a forum they will attack the author of the post in any way possible. They often create 90% of the flamewars out there as a result. Mostly due to them not having a sense of humour. They do these things because they are too stupid to understand a joke, and will never be smart like the one who told or wrote the joke.
If a strong serioust finds a funny Wiki article they will believe it. If someone posts a joke on a forum, they will take the poster seriously and believe whatever the poster wrote. In fact, if they are reading this article, they all have tiny penises even the women, and the black helicopters are coming for them led by Rambo and Mr. T. See now they are all checking their groin and being paranoid that some group is out to get them. Isn't it fun to mess with the strong seriousts?
They are often victims of Change Management in all of the forms it is available in.