Purple Day has a pretty interesting story. According to their website:
Cassidy Megan created the idea of Purple Day in 2008, motivated by her own struggles with epilepsy. Cassidy’s goal is to get people talking about epilepsy in an effort to dispel myths and inform those with seizures that they are not alone. The Epilepsy Association of Nova Scotia came on board in 2008 to help develop Cassidy’s idea which is now known as the Purple Day for epilepsy campaign.