When I first got to Spain, right away I noticed that Spanish people had very long names.  From the beginning, I learned that when a child is born, he/she receives the first surname from the father and the second surname is the first surname of the mother.  This seems very simple, and for this reason, I accepted this difference without any more questions. 

e.g. Juan Martínez Escudero + Marta Villanueva Cortés => Juan Martínez Villanueva

After doing a little research, I found out it can get quite a bit more complicated than what I previously thought.   What happends when two spanish people get married??

Well...

If Teresa García Ramírez marries Elí Arroyo López, she doesn't change her name, BUT it would be extremely common for her to add "de Arroyo" (literally, "of Arroyo"), making her name Teresa García Ramírez de Arroyo. This is why the names get so long!!  Now...imagine that Teresa´s name is actually Maria Teresa (it is very common for Spanish women to have two first names as well...commonly the first being Maria.) 

Now the final result is Maria Teresa García Ramírez de Arroyo!! That sure is one long Spanish name!!!