There are over 50 million people in our world today that have Epilepsy/Seizure Disorder. Chances are, you probably know someone that has epilepsy and they might not even be telling you because they are too afraid or embarrassed to.
Anyone with a brain can have a seizure at any point in time in their life, even if they've never had one before. Not all seizures are genetic, up to 50% of people do not know and/or will never know what caused their seizures in the first place (idiopathic seizures/epilepsy).
Not all seizures are convulsions. Not all people with epilepsy have a light sensitivity. Be aware for other signs such as wandering aimlessly, confused speech, picking at clothing, smacking the lips, chewing the cheek, staring blankly, lack of responsiveness, etc. if something looks strange/wrong, it probably is - make sure the person experiencing these symptoms is okay.