First post

I've been playing for just over 4 years, I play most of Paul Gilbert and Malmsteen's work and can play their stuff to the point where i add my own fills and variations.

I've since only learned my most basic chords and the scales, i've never learnt anymore because I just jumped straight into metallica.

Throughout those short years I've picked up octaves and how to move my chords and scales around the fretboard

Do I really need to further my theory knowledge? (I know it will be very helpful)
Quote by Sazeth
Do I really need to further my theory knowledge? (I know it will be very helpful)

Kind of answered your own question there didn't you?
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Quote by Master Foo
“A man who mistakes secrets for knowledge is like a man who, seeking light, hugs a candle so closely that he smothers it and burns his hand.”

So are you asking whether or not you should stop at just Metallica and basic theory? I would definitely say the answer is no. There's so much beyond basic scales and chords, and even besides that, you'll always be working to improve even the simplest aspects of your guitar playing.

Just because you skipped some steps and did ok doesn't mean those steps aren't important.
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Well I guess you don't NEED it, but it would sure be worth learning, and would probably make your playing alot better. And really, I can't see any reason not to learn it other than lazyness.