Ever since I started learning languages I had a relative ease when it comes to understanding different words, structes and language particularities. I always thought it was just something I could not understand nor explain in depth. However, recently I have come to the realization of this "relative ease" as a result of me learning about Latin and Greek roots when I was young.
Knowing about Latin and Greek roots can have a special impact on many things when it comes to learning a new language. Of course, it does not have to serve to anything, but the fact that it actually does deserves to be aknowledged.
To begin with, about 85% percent of the words in spanish come from ancient Latin and Greek, therefore knowing the roots will help you understand words from different speciality fields such as medicine and science. This, along with prefixes and suffixes will get you a long way to the understanding of words just by looking at them.
Just to name a few, you can understand if a word is implyin possibility, action, qualities, pain, power, sound or passion for something.
Nevertheless, learning Greek and Lating roots will not only help you learn spanish. Languages such as French, Italian and Portuguese come from ancient latin. But also German and even english are related somehow to these languages.
To sum up, learning this is not a must, is not mandatory at all, but I can assure you it will help you improve your reading skills, your grammar in the language you are currently working on and much more. You will start understanding words you had never heard before of and linking words from different languages with the words you know.