The search for knowledge is born out of necessity. Memorizing scales, chords, tunes and such is meaningless to anyone who cannot see a useful application in these elements of music. Here are a few "scenarios" and the "elements" that are more often than not required, due to the nature of the music.

Rock:
-Pentatonic scales
-Open, Barre, and powerchords, arpeggios for bass players
-Notes on the fingerboard (to a small degree)

Jazz:
-Extended chords
-Scales & Arpeggios, both traditional and altered
-Sight Reading
-Notes on the fingerboard (to a complete degree)
-Substitutions
-Styles (bebop, cool, afro-cuban, ragtime etc)

Classical:
-Sight Reading
-Complete knowledge of the fingerboard
-Styles (Medieval, Renaissance, Baroque, Classical, Romantic, 20th century)
-Major, Minor scales and arpeggios, and the minor variations.

If you find yourself wondering why you are not interested in Theory, maybe it simply would not better your life in any way.

But here is some food for thought:

Let's say you were a killer sight reader, that could read down a Hindemith tune, while falling out of an airplane. What sort of opportunities would open up? Every major city in the US, and most of the minor ones have Opera houses, theater companies, and Classical and Jazz Orchestras that are dying to PAY you to do this. In most cases, quite handsomely. You might be thinking, these opportunities never arise in your life, so why waste the time? Well, it doesn't work that way. You learn how to do it, then the jobs show up. You will never get the call, BEFORE you learn the skill. This, for those of you that just waded through this wall of text, was the heart of my point.