THE question in the title was asked be someone.
This is my answer.
I speak and write English and Tok Pisin (a creole) – languages I grew up learning.
I learned French and enjoyed the experience and know a few words/phrases in a number of local dialects in my country.
With that experience, I say learn Spanish. I think everyone who has watched Hollywood movies over the years would have learned a handful of phrases – even though they may not know exactly what they mean.
(The same could be said of Spanish songs too – some are popular.)
Some examples of common Spanish words/phrases that we hear all the time include:
Por favor – please
Hombre – man
Adios – good bye
Amigo – friend
Gracias – thank you
Hola – hellow
Si – yes
No – no
Por qué – Why?
So, I say, learn Spanish. It will be fun.