Instinct is something which transcends knowledge. We have, undoubtedly, certain finer fibers that enable us to perceive truths when logical deduction, or any other wilful effort of the brain, is futile.
Careful now, meth is like love. It knows no borders, no age, no race or creed. Meth just is. Who are we to assume this whole thing wasn't a meth fueled nightmare from the start? Kid tried going full John Chewiesak on his ex, boom box and all.