Huh, alright then. Granted, it's only as approximately flat as we can measure (there's a margin of error in there), but there's no reason to assume it's closed instead of open (I still find it intuitively improbable that it is actually flat, given a 2% margin of error, but hell if I'm qualified to argue it).
The universe has properties that allowed life to flourish in order for us to perceive those properties.
(Eg. if a universe has properties that do not allow for life--such as being so highly curved as to be a finite volume containing a single star--then it effectively doesn't exist: it can not be observed from
outside (by definition) and there's nothing
inside to observe it either, hence it doesn't exist. The universe exists because we exist to see it and has properties that allow for life because we, as living being, can observe those properties. The universe being flat--that is, perfectly 100% idealy
FLAT--is because if it wasn't flat, it wouldn't be stable: if it was closed and curved it would eventually collapse in on itself; think about those snap bracelets: flat until you bend them, then *snap* curled up tight, the universe is like that and has properties such that if it wasn't perfectly flat, it would curl up into a tiny ball and cease to exist. Or so I've been told).