Albus Dumbledore calmly regarded the twenty-five (well technically twenty-five and a half) year-old woman in front of him.
"Ah, another self-insert I see." He said. "Considering the fact that you were born in the December of '83, it would seem that you actually arrived just in time for your first year."
Turning to a nearby cabinet, he rifled through it, tossing various items including a sextant, a globe of the moon and an orange and blue sock across the room before pulling out a vial.
"As part of our standard enrollment procedure I must request that you drink this." he said holding the vial out in front of him.
"Okay." the woman said trustingly, taking the vial and swallowing its contents in one gulp.
"Tastes just like chicken. I hate chicken." she said.
Ten seconds later there was a loud pop and the woman was replaced by a rather freaked out eleven year-old of above average height and weight with short brown hair, blue-green eyes behind a pair of glasses with plastic tortoise shell frames, and pale skin that burned if she was out in the sun for more than ten minutes. She was dressed in the same style outfit she usually wore since she was a toddler, namely jeans and a T-shirt.
"Where the hell am I, and who the hell are you?" she shrieked, backing towards a wall in her panic.
Dumbledore smiled serenely. Fans who had turned eleven before the Harry Potter series first came out were so much fun.