Argh, Essay Question...

Just had my first essay question since I've been back in school. You must remember I've been out of school for 7 years and this is my first semester back. Having been rather active online, in forums, writing blogs and stories and the such, I don't mind writing, but it's just that I'm so used to having as much time as I need to finish something I'm trying to say. If I am asked to write five paragraphs to answer a question, I wish to write the best five paragraphs I can possibly write, for better or for worse. How can you do that in less than 30 minutes?! It's not possible! It drives me crazy to leave holes. Oh well...