March 28, 2001:
August 5, 2001 (the continuation of the part I quoted earlier about Oskar kissing his mirror image):At some point I also have to clarify the nature of Eli's hunger. Eli becomes hungrier and hungrier, needs more blood to keep his advanced form of existence going. Eventually Eli is capable of quick, extensive transformations and this also heralds the need for hibernation. The cells' intense activity, his body gets used up if he doesn't rest.
The last two sentences are the relevant part. Of course, JAL didn't exactly apply this consistently given that Eli needs an invitation to the pool but not the hospital, while in the film it's the other way around, and both of those are public buildings.It starts with Eli standing out in the stairwell, explains that he needs a new invitation, because it's a new entrance.
"Sup."
"Hi."
Oskar goes into the apartment.
"Oskar. You have to... invite me."
"But you have... the window..."
"This is a new entrance."
"What happens if I don't?"
"Do you want to see?"
"... no."
Maybe something more on this. It's a vampire limitation that's very difficult to understand and it would be fun to come up with a good explanation. All the rooms that people perceive as theirs. Not public buildings.