being able to hear the intervals will make implementing any music theory you know much easier and more natural.

the propblem with most people who are understand their theory s they cant implement it. to do so u need to be able to think on the spot and hear wat is in the music. if u cant ur left guessing or analysing the song for ages before u can put anything down on paper. and this kinda destroys the whole improvisation process. i too am tryiong to learn my intervals. one day i'll get there.