Of course you can learn!
It begins with literacy.
See here Penty, some of us have a natural 'talent' as you put it when it comes to music, but didn't learn the basics early on that many others take for granted. That limits the expression and unfolding of any latent talent.
Self learning can be a bitch when the very people who could most speed your progress by sharing their work and knowledge with, are the very ones who get all arrogant and protective of what they know.
Excuse my indignation.

It pisses me off though when people make things more difficult than they need to be and - whether with intent or not - close off opportunities and encouragement for others.
Romanticizing musical knowledge, is what it is.
You can immerse yourself in music, and learn from what you hear what others have done before.
You can take a class, or a workshop, or spend time working on music with others who have more experience.
You can brush up or learn for the first time Musical Literacy : how to write and read music, what a melody is defined as....
Find a good teacher.
You read books, and you write, if you want learn how to write.
You listen to music, and write music, if you want to learn how to write music.
Whether it will be 'good' or not is not the question.
*gets off angry high horse*