PSA: WE HAVE A PATRONUS TEST 

Mine is a white swan. The selection process is a bit random though.

Grey squirrel. Small and annoying, like me xD

I thought that too at first. Upon reflection though, it's not necessarily meant to be an animal you're fond of or that represents your personality- it's more of an embodiment of your happiest memory. That's why the questions focused on that, I think.

It didn't actually ask anything about the memory though. It was more like choosing between random words.

And I thought it was meant to represent your true personality. It doesn't reflect the memory, or the form would change as the memory you use changes. Harry uses several different memories and ideas to make a Patronus throughout the books, but his is always a stag.

Hmmm. Maybe a bit of both. JKR wrote that it's a "pure, protective magical concentration of happiness and hope", "the recollection of a single talisman memory". Pure conjecture here: Harry's stag might represent his personality (noble, etc) but it also represents- as a deer, like both his parents- connection to the people he loves. When he was conjuring a Patronus, he always thought of his loved ones, be it his parents, Sirius, Hermione and Ron, etc.

The form can change though, and maybe it's when the "theme" (for want of a better word) of your happiest memories change. Snape's and Tonk's Patronuses both changed when they fell in love. Maybe it was because their happiest memories were now very different- that of Lily and Remus, respectively- and their Patronuses changed to reflect that.

Like I said, pure conjecture though. I have no idea how Ron would get a jack russel terrier from his happiest memory, for example. Before I thought about the "embodiment of your happiest memory" hypothesis, I always thought it was because it represented his loyal nature.

Anyway, maybe it depends on both. Interesting to speculate on.