I have to write one for this program I'm applying to, and I have no clue what to do with it. I don't even know how to start it.

The application is really thorough so they already know a lot about my accomplishments, the quote from the site is: "An application such as this is better at telling us what you do than who you are. Therefore, we ask that you include a written personal statement about yourself that will help us get to know you better and fill us in on anything our application might have missed. "

Are they asking about hobbies and generally what I do as a person, or is that too personal (of course I would make it relevant to the position I'm asking for...)? Is it supposed to be more formal than that?

And how the hell do you open one of these things up? Any opening line I can think of sounds like either fiction or an AA introduction. I'm so stressed, deadline is Nov. 1.
Do a search, there will be things helping you out with it. Either explicitily or implicitily. If it's a big company it' s likely someone would tell you exactly how to write it.

I have to write one for my UCAS application...
On vacation from modding = don't pm me with your pish
Young padawa....you must talk about yourself...stay on topic or no cookies for you young padawa...