Ok, it's a typo.
We have established now that it was a typo.
Back on topic,
1. I have an above average IQ (You probably do as well)
2. I'm serious 78% of the time.
3. I'm not immature when I'm serious. (I don't act super-immature when I'm not)
4. My jokes shouldn't classify as jokes, because they are so dull.
I'm not talking about actual IQ, I'm talking about mental maturity and language comprehension. For God's sake, you haven't even figured out how to get an avatar yet. I don't know how old you are, but I would guess around 11 or 12 based on how you act. Whether or not you're serious doesn't contribute to maturity. Complete jokers can be mature and fun to talk to, while dead-serious people can be dumb and cringe-worthy. Also, is not up to you to gauge your own maturity, it's up to those around you.
Side note here, don't take this too harshly. A lot of us were like that when we first joined, too; that's because we were really too young to be on the forums and I reckon it's a similar situation for you. If you don't have pubic hair (and ESPECIALLY if you don't know what that is), you are too young to be on the forums. This is for your own good as well as ours. Just leave and come back later. Again, don't take this the wrong way. You're not a bad person, just... come back later, okay?