i teach myself how to play song by listening to them and matching the first pitch. then i just work it out. why can i do that and some people can't?
Such a talent is often called "playing by ear". Some people have this talent and so they don't really need to be able to read music to replicate songs they hear.
Many people will do "ear training" as part of their formal musical training (especially for types of music that don't have formal notation), but not everyone has a natural talent for it like you do.
The skill you have may be similar to the concept of audiation… where you hear and comprehend music even when it's done playing. Audiation is beginning to be considered an important skill in music education.
Hope that helps some.