There´s always going to be cultural references and language stuff that you won´t be familiar with if you haven´t been brought up in a country. For example, I blame my inability to master the past and subjunctive tenses on my parents not having read me bedtime stories in Spanish (an unreasonable complaint given the fact that they don´t speak Spanish but nevertheless....)
Until I watched the movie the Tooth Fairy on a bus journey to Granada (a.k.a
Rompedientes o Hada por accidente) I didn´t realise that the Tooth Fairy didn´t bring the money in Spain but, in fact, Ratoncito Perez. Cute! There´s a museum in his honour on Calle Arenal, go visit, it´s suitably random (and free if you just visit his statue on the ground floor) I brought my boyfriend but children would probably be more appropriate!