the way i've done it is that first i click in the text-entry box. i then start pressing the keys on the keyboard with my fingers. sometimes the sequence of keys i press forms an eloquent answer, for the most part it's just illogical rambling. when i'm done, i click the submit button with my mouse. then i fart, waft the smell towards my face, and bask in the fumes and feel proud of myself.
i have found that this is the best way to answer those questions. you should try it.
What I've done is go to the school's website and browse around to see what interests me. Take a look at the curriculum, opportunities for students (electives, study abroad, etc). For example, for GW I got really excited when I read about all the possibilities for doing fourth year electives abroad, so that was something I talked about.
You should put a little thought into this. If you only applied because it's a 'safety' school, because of its 'name', or because you just felt like adding it, then you pretty much just wasted your money. Adcoms aren't dumb enough to let you in if you have no idea what to expect from their school or specifically why you were interested in the school in the first place.
Just try to keep in mind how you would come off to other people. When you or others read your essay, how do you think you come off? Vague, knowledgeable, interested, aloof, etc? There has to be something about the school you like or are interested in knowing more about because if you just quote things from their website as part of your hyperbole, it'll be pretty evident that you don't have the slightest idea what you're talking about, no matter how convincing you try to make yourself seem. Adcoms aren't omniscient but they do have pride in their institution. Don't be condescending.
Just be honest and mention what drew you to the university. If you're really that stuck, then fine, look up something on their website and just mention an aspect of medicine that sticks out in your mind. Yes, you might have to put in a tiny bit of effort to do a little research.
Otherwise, you are just giving them a donation (thanks!).