Sergi Roberto capped off an impressive start to the season with a brilliant performance in El Clasico. But it was not always easy.
Fans sometimes assume that a footballer's development is more or less linear. That a player who is good when he is young will necessarily improve at a more or less regular rate until he's about 30, then decline more or less regularly. This isn't the case at all, and it's impossible to predict. You have players like Michael Owen who become world-class before 25 but regress just as quickly. Some, like Diego Costa, live in relative obscurity, rocket to stardom, and fall back a bit.