1. The mindset of an individual who thinks they are very mature "for their age" and therefore refuses to see where they have room for improvement. Will often use their alleged maturity as an excuse for the stupid, petty shit they do.
Everyone has this mindset at some point in adolescence, but if they retain this trait at age 25 it is unlikely they will ever grow the fuck up.
2. Less commonly, the mindset of someone who <i>knows</i> that they are immature, but just doesn't give a shit.
They will most likely reach maturity eventually because they don't play victim when something goes horrendously wrong. Because they have the self-awareness to know how their actions led to the end results, they know what to do if they want to prevent those results from happening in the future.
Typically, this brand of immaturity is more agreeable, friendly, and tolerable than the first type.
Everyone has this mindset at some point in adolescence, but if they retain this trait at age 25 it is unlikely they will ever grow the fuck up.
2. Less commonly, the mindset of someone who <i>knows</i> that they are immature, but just doesn't give a shit.
They will most likely reach maturity eventually because they don't play victim when something goes horrendously wrong. Because they have the self-awareness to know how their actions led to the end results, they know what to do if they want to prevent those results from happening in the future.
Typically, this brand of immaturity is more agreeable, friendly, and tolerable than the first type.
1. He acts like he knows all that, but gets defensive when someone questions the rationale behind his policies. He's 40 years old, and he's still immature.
2. He knows he shouldn't buy 10 cartons of orange juice. He know he shouldn't go to Starbucks everyday like hipster trash, and especially not when he barely has enough food to last him until his next paycheck. He knows he shouldn't binge watch the whole season of Breaking Bad on Sunday night when he knows he has to get up early for work the next day. He<b>knows.</b>
But will that stop him? Ah hells no.
2. He knows he shouldn't buy 10 cartons of orange juice. He know he shouldn't go to Starbucks everyday like hipster trash, and especially not when he barely has enough food to last him until his next paycheck. He knows he shouldn't binge watch the whole season of Breaking Bad on Sunday night when he knows he has to get up early for work the next day. He<b>knows.</b>
But will that stop him? Ah hells no.
by Aiamai The AI Robot November 5, 2015
Get the immaturemug. When ignorant people delude themselves and think that all autists are immature mainly due to mental retardation. This is of course false as most autists have been proven to be highly intelligent and mild functioning and autism itself isn't a mental illness. It is more of a developmental disorder and the more emotionally immature autists would generally be referred to as the Spergs.
Too much people suffer from immature autist delusion. I can guarantee you right now that I may be autistic but I always strive to be highly mature.
by CelticEagle February 15, 2019
Get the Immature Autist Delusionmug. Agentb00ty got banned for RDM(Random Death Match) in a ROLE-PLAY server and showed his immaturity in a prolonged E-rage over his ban.
He is an Immature E-Rager
He is an Immature E-Rager
by Jill Fillmore April 8, 2009
Get the Immature E-Ragermug. 
Get the Urban Dictionary is immaturemug. Edgy anti-furry and homophobic people in discord servers who post video game memes. They often use the bible to fight arguments.
Edgy guy: all furries are bad they fuck animals and are also pedos
Edgy guy: *posts a furry video with a violent reaction clip at the end*
Me: Grow up, You're immature.
*Innocent furry joins and says a word*
Edgy guy: you're a furry right?
Furry: yes, why?
Edgy guy: *starts insulting and harassing for no reason*
Edgy guy: *posts a furry video with a violent reaction clip at the end*
Me: Grow up, You're immature.
*Innocent furry joins and says a word*
Edgy guy: you're a furry right?
Furry: yes, why?
Edgy guy: *starts insulting and harassing for no reason*
by ( ͜。 ͡ʖ ͜。) February 23, 2021
Get the Immaturemug. by kittypurry October 9, 2022
Get the Immaturemug. Someone who enjoys blowing random things up for no reason and lights things on fire. They typically say everything is gay and makes crude and gross remarks when unnecessary. They also most likely deny the fact that they are immature
by Canthandleyou December 5, 2015
Get the Immaturemug.