There’s also the fact that the ages from about 20 to majority at 33 have their own name among hobbits (“tweens”), and are regarded in much the same way that we regard the teens.
And I had a total brain fart. My 800 math SAT score was almost forty years ago, and apparently I’ve lost a lot of ground…
"But pity stayed his hand, It’s a pity I’ve run out of bullets.
There is still nothing here that couldn’t be about a twentysomething year old human. As far as Pippin’s best friend being a 10 year old, I felt he was just as close or closer to that 10 year old’s dad.
Or a period of wild abandon and reckless indulgence. I don’t know how old you are, but most twenty year olds I know (and was) spent the decade partying. It was nothing to go on a drunk on a Tuesday. When I turned 30ish, I quit “partying” as did most of my friends (who had kids by then) and became a responsible adult. We are no different than Hobbits. My point is that our culture has this arbitrary 21 year point we call adulthood, but we spend a decade as children who can drive and legally drink.
I knew there was one. Couldn’t think of it. Still, it was an idealized time with “little” sickness. Even if we grant the Hobbits a slightly longer lifespan, it still doesn’t necessarily follow they mature slower. Elves are specifically mentioned, but they live 1000s of years. All we have about Hobbits is circumstantial evidence.
I could be wrong, of course. But I don’t think it’s the slam dunk everyone thinks it is. Hobbits are pretty much just humans with short stature and hairy feet and not a special race like Elves or Dwarves. We have no evidence they go through puberty later than humans. All we have is this vague “come of age” phrase that can mean anything. I suggest that it means when they come of an age where they settle down and become responsible citizens. Our 21 really has no physical significance in our maturity.
You’re probably right, thinking about the etiquette of the party invitations: Bilbo sent out fancy invitations by mail and got written acceptances by mail* (resulting in the need for extra postmen to handle the unusual volume of correspondence). Working-class hobbits who couldn’t read and write simply wouldn’t have been part of this social exchange.
Although I bet that there was a sort of informal blurring of the boundary between servers and guests at the lower social level, and that the dozens of working-class hobbits who would have been helping out with the refreshments and so forth were also taking some time now and then to enjoy the food and entertainment.
*[hostess rant] The things that someone in Tolkien’s social environment could just blithely take for granted. Have you tried getting RSVPs, even electronic or verbal ones, out of the people you ask to a party lately? (grumble grumble) [/hostess rant]
slight hijack…two days and filming starts on The Hobbit!
I thought they were already filming. 
They are doing it in spurts. They are coming back from a break.
Y’know, I honestly never actually made that connection. I knew that Bilbo’s invitations were mostly via mail, and I knew that the Sam’s dad considered literacy uncommon, but I somehow never put 2 and 2 together.
As an aside, when they made the movies, they really should have given the head electrician a cameo as Hamfast Gamgee.
Ewww.
“Practically everybody living near was invited. A very few were overlooked by accident, but as they turned up all the same, that did not matter.” – “A Long-Expected Party”.
One must wonder, though, whether Bilbo’s (or Tolkien’s) notion of “everyone” would correspond to our modern notion. One is reminded of the Victorian era when everyone had live-in servants… Except for the majority of the population who were the live-in servants.
Not necessarily significant. Especially in a class-based society, “everybody” generally means “every member of the particular social groups for whom participation is appropriate” rather than “every living person”.
When the lady of the house in, say, a British drama set in a wealthy London suburb in the 1930’s says “We’re having a dance for Priscilla on Friday, I’ve invited absolutely everybody in town”, she does not mean that she expects the housemaid’s mother to show up among the guests.
ETA: Aaaaand scooped by Chronos. 
Well, there’s your insistence on the one hand that things simply must be as you theorise, and on the other hand there’s what the Prof wrote as quoted above and also:
Prologue, Concerning Hobbits: “Bilbo and Frodo Baggins were as bachelors quite exceptional”.
Farmer Cotton isn’t a typical Hobbit either, he knows Tom Bombadil. His farm hands seem right up for a scrap when it comes to it though.
Farmer Cotton doesn’t know Tom Bombadil; that’s Farmer Maggot.
Oh God. buries head in hands A schoolboy error on my part.
Like my taking 1380 from 1420 and getting 30? Yeah, I wouldn’t know what that’s like.
Receiving presents in honor of Bilbo’s birthday/departure != receiving official invitation to attend Bilbo’s party. The guests did receive various favors and so forth at the party itself, but there was also a big distribution of gifts after Bilbo was gone.
Like I said, there may well have been lots of working-class hobbits sharing the fun on a lower rung at the party. But “what the Prof wrote” about the invitation-and-acceptance process quite clearly seems to indicate that at least the vast majority of the official guests were literate. That’s not my “theorizing”, it’s what’s in the book.
The thing is that it’s not immediately obvious from Tolkien’s descriptions exactly how the different social classes of the Shire interacted on all occasions, and different cites quoted in isolation can easily seem to point to different interpretations. Reasonable interpretations may disagree without either one of them being as obviously and indisputably right as you seem to think yours is.
What seems to me most reasonable, based on the totality of the descriptions, is that Bilbo’s many guests were mostly hobbits of his own or similar social class, and that neither they nor their working-class neighbors would have seen anything incongruous in describing such a party as “inviting everybody”.