It's interesting, in a sense, what your mind comes up with. A number of old-school writers would drink or drug themselves 'for inspiration'. It is true that your mind can make odd and occasionally (very occasionally) brilliant insights when drugged or feverish. However, you have to make sure your fever dreams stand up to daylight. Dream logic isn't real logic.
I've had characters come to me in dreams or when I've been sick. (Yes, I have an over-active imagination. This surprises you?) Sometimes they'd speak to me and argue about how I'm depicting them. Sometimes they'd act out scenes I hadn't written. But very rarely have these scenes stood up to closer examination.
Real inspiration, for me, strikes when I'm out walking or working out or having sex. Writing is lucid dreaming for me. But I need both halves of my brain to be awake for anyone else to see the dream.