When a trucker is driving on the outside lane and sees a beautiful woman on the inside lane. She is a one hander because the trucker has one hand on his rig and his other hand on his other rig.
This mainly applies to television series that have ran for over a year. One episode number one fans are people who see one episode of a popular television show and try to integrate themselves into the fandoms of said show much to the annoyance of actual fans of the show who have been there since day one. They will usually try and strike up a conversation with an actual fan but most fans are not interested in somebody who knows barely anything about the series and will ignore them. This usually leads to them becoming aggressive over not being included in a fandom they know nothing about and will often accuse the fans of gatekeeping.
“Omg I love this show so much! I ship this character and that character!”
Real fan: “dude you’ve only seen one episode, stop acting like you’re a die hard! You are literally one episode number one fan.”
One percenter can sometimes mean the one percent of the population that takes up new technology first.
People who line up for days to buy the latest iPhone before everyone else gets it are one percenters, not because they are the one percent richest or the one percent most intelligent but because they have a constant need to feel special or exclusive.
My neighbor just installed a TeslaWall. It will take him 150 years to pay it back in power savings but I guess being a one percenter is priceless.