Nice comments, all. I always appreciate your feedback!! And yeah, studies aren't everything... sometimes I like to see what data/patterns they come up with, though, since I'm a social scientist nerd.

(Hence I like seeing how individuals on TFP deal with these life decisions, gives me much more perspective.)
Supple Cow, I see what you mean. Seems there are (at
least) two approaches to this whole thing... people either see living together as a test-drive, and therefore very subject to change (these folks are prob most likely to get a divorce later on??); or they see living together as the next most logical step towards quite possibly spending the rest of your life with someone you love, and therefore getting married to them later wouldn't change much anyway. ShaniFaye's "married in our hearts" sentiment rings most true for the second option, and for me personally... living together, for me, is sort of a spatial representation of being engaged, maybe??... pretty much to the point of no return, and certainly not thinking about "returning" unless something drastic happens.
But I'm still curious!

Why do you all think some people live together first while others jump into marriage right from the get-go? Is it just some people aren't ready to make that commitment while others make it, ready or not?