To be quite honest, I memorised all my essays/creatives (first time everr so I felt horrible) and I went out with really good marks.
Just keep in mind that you NEED to be flexible with what you've memorised (be prepared to do some major overhauling very quickly) and make ANY link to the question you can (I memorised my Hamlet exam essay which was also incidentally about 'what it means to be human' and I got full marks by making constant if tenuous links to the question). And what I did in Ext 1 exam (which was also incidentally a quote) was that I started with the quote and weaved the critic's name and quote all through my topic sentences. And it's preferable that you don't memorise an introduction and conclusion. Bam 25/25 for that essay...
Coincidentally, aphorae - what school do you go to?
What I'm planning to do is to not only memorise the essay, but also brainstorm other thesis statements, other techniques - my teacher uses this analogy where we are the 'computer hardrive' (while she is the best teacher, she does NOT know technology) and we 'download' the relevant information upon exam. Just try and know everything vaguely, and a few ideas well