Quote:
Originally Posted by
XanaSnape 
"Excellent questions. You must use one clear, strong, happy memory. More than one memory splits your focus and therefore weakens the charm, usually to the point that nothing is produced. Feel free to try it with multiple memories, and compare your results. The classroom lab is the time for such experimentation, after all. But you will find that one powerful memory is the key to creating a patronus, especially a soild patronus charm." Kazimeriz walked around the class, watching his students as they began their patronus practice.
Ooooh. So that was why hers wouldn't last? But chosing one happy memory? Just one when she had soooooooo many now? She screwed her eyes tightly closed and when she opened them she knew exactly which one would work. She shot a quick look at Copernicus and gave him a mischievious little grin as she heard him ask a question, but didn't let the question distract her from casting with the same gentle movement as before, "Expecto Patronum!"
Definitely a scorpion.
She held her breath, wondering if it was going to last.