Another theory about this is that chell is the ONLY test subject (or the only one left) and is cloned by glados from one death to another and so she goes further and further in the chambers leaving some clues on her way out of some of them ... like the well known 'the cake is a lie' wich is ultimately wrong since cake iss,in fact, real, proving the player is incarnating the last and most reliable of the 'chells' since you're supposed to go to the end of the game, meet glados and get out...
This explains the 'hello and again, welcome" at the start of the game ....
It could also explains why she has a 'subject name ' and 'subject hometown' instead of a real name and hometown since she's a clone she technically has none ....
And also, the unsatisfactory mark on her test report followed by death , seems like death's subject is a routine ...
Some other think she's an android because of the combat android test chamber ...well i prefer the clone version :)
Oh and sorry if this has already been posted somewhere ...
You should quit while i'm ahead...
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