Well, I happened upon a thread that was using word play by turning the word "swag" into a acronym for something distasteful or something to that extent, when I got curious about the true definition of Swagger and Swag (similar words though not exactly the same). Obviously, as that was a joke thread, I wouldn't want to waste the post in there, rather, I make my thread about it for the whomever has had their curiosity piqued by this word.
With a simple dictionary check the word "swag" can mean a specific type of wreath but is more commonly used as the verb meaning: to move heavily or unsteadily. (like, "to sway") This, in and of itself, would seem incredibly unlikely to become what it means today from where it was, and if it stayed as simply meaning to "move unsteadily" it may have never became popular what so ever. However, it interested me to know that a key player in inventing what Swag means today, was actually .
That's right, the magnificent man of writing magic invented the way we use the word Swag today. He first used it in "A Midsummer Night's Dream" in the quote: "What hempen homespuns do we have here" - Puck
He used it as a verb meaning "to walk or strut with an insolent air" or simply: To walk arrogantly, as in, with an undeserved sense of pride. Obviously these "Homespuns" that Pluck was referencing to were walking like they owned the place and he told it to them.
Since then "to walk arrogantly" was an obscure word that fit perfectly to a contemporary rapper's advantage. Obviously, some big time rapper gave this obscure probable SAT word breath and made it appeal to the young. Swag, today, is just a shortened version of "Swagger" so it is not to be confused with the wreath type of Swag, which is the older definition that doesn't really apply. Therefore, to have "swag" means to have an insolent air about you in your walk or manner. Or at least, that's what it more commonly stands for for today's youth.
So technically, anyone can have "swag" (not the wreath though) so long as they act like they own the place. Why someone would admit to acting like an arrogant, jerk, you got me. But hey, it's our "gnarly", our "Wack", our "out of sight!" Sure we hate it now, hate it like our parents hate disco, but we'll laugh at it later when it falls out of style, so best have fun with it.