Your Instrument and Applying Music Theory
With each Musical Instrument there are several factors that are associated with learning music theory.
Each instrument has it own unique way of addressing how notes will be played, what the configuration of fingering for a scale will look like, playing a broken chord staccato or legato, and other such nuances.
But what usually controls the vast majority of learning an instrument is the specific techniques of playing. Whether it be a specific picking of a string, fingering of a fret, shaping of the lips, breathing properly, or hand action on the keyboard, the fundamental math of theory remains the same across all instruments.
The lessons developed for getting it down cold are created to give you the base foundations of music theory so that you can focus on your specific instrument techniques.
Therefore you get know the theory and when working on a song or fake sheet you have the foundations available to you so that the learning process actually goes faster and the theory is secondary.