That would be REALLY uncomfortable to sleep on, I bet.

Not sure sure if hitting the hay, or hitting the books.

@Derp1a  
“Just one night I get to sleep in the castle as princess and now I have to stay in the library again.”

And she still lives in a library

Twilight Sparkle has a natural affinity towards books.  
As rigid and uncomfortable as a book bed may seem to us mere mortals, that bed is super comfy and provides adequate sleep for Twilight. (Although I have not seen the movie either, I am just assuming the adorkable Twilight would be comfy on a book bed.)

Those must be big books. I’ve tried to make a bed with stacks of pillows. Tell you, it wasn’t comfortable and it was uneven.

Book bed, the natural evolution of the book fort.

@JJMDude  
It wasn’t being shown anywhere near me, so I’ve only seen the second hand postings about it.
 
Being cowed by Celestia’s counterpart is actuallly a very good, character appropriate reason for Twilight to jump through the hoops. Lord knows she’s done dumber stuff out of reverence for her teacher…
 
As for why Sunset dosen’t steal it, despite the whole evil overlord thing she’s trying to put together, I’m going to chalk that up to her time in the human world making her a lazy, conceited bitch. Man, the more I learn about her, the more I conclude that she’s really terrible at the whole villain thing. At least Sombra had the excuse that he got a magic lobotomy.

@Trickquestion  
Don’t know if you’ve seen it yet, but in the movie, while it IS a plot issue that she doesn’t just try to break in (and nor, for that matter, does Sunset Shimmer) in Twilight’s case she tries to get it back by speaking with Principal Celestia.
 
Now, Twilight HAS been known to say “fuck the poh-lease!” when presented with a huge enough crisis, but that is by and large the exception. Not only is she basically breaking set rules and committing out and out theft (though swapping it for the ACTUAL Fall Formal crown wouldn’t have gone amiss) but the scene suggested she was rather cowed by the presence of her mentor, even if it’s not REALLY her mentor. And on top of that, Principal Celestia offered up a perfectly legitimate means of procuring the crown through the Formal vote, and I have to imagine that it appealed to her greatly.
 
…and, naturally, the ultimate reason is that the movie would have been over otherwise, barring Sunset Shimmer stealing the crown back first and making this into a very different movie.
 
It’s contrivance, almost certainly, but hey: they had a message to present and a story to tell, and I think it can be worth a few blemishes to make something like that come together the way it did.

@SeraphimDawn  
Exactly! They’d see some crazy horse lady show up, the office would get called, records checked, police summoned, the pepper spray gets broken out and then nobody’s having fun…

@Trickquestion  
In my old school, teachers pretty much know every student be face.

@SeraphimDawn  
I’ve been getting the impression Twilight isn’t actually attending the classes, and is interacting with everyone during lunch. Because having her actually go into random classrooms would be incredibly stupid, seeing as teachers would not only immidiatly not recognize her, but a quick check would reveal her non-registration in this school.

@Trickquestion  
Yeah, and they didn’t call the authorities.

@SeraphimDawn  
Dorms in High School? Ain’t nobody got time for that!
 
Besides, Twilight’s just some incredibly bizzare hobo who wandered on to campus one day. She get found out pretty quick if she tried to use the actual school services due to her complete lack of records.

How is she even allowed to do that? Don’t they have dorms?

Where did she swipe the sheet from?

If she could break into the library in order to spend the night there, surely she could have broken into wherever they had the crown and stolen it.

I hope those are books about politics.

That looks even less comfortable than the floor