You were quite frustrated. You'd been trying for a good half-hour, and yet you still couldn't produce a full-fledged Patronus. Hermione noticed your furrowed brow and came over, offering to help, and you explained to her your difficulties. She gently took hold of your wand wrist and raised it, standing close behind you as she instructed you to recall your happiest memory. You glanced back at her fondly, then said you were ready, and as soon as you let that one perfect memory of you and her fill your mind, you spoke the incantation- and this time, you succeeded.