Regarding hallucinations ... I have had some incredible ones on my long rides!!!
But Rowan has helped me limit those with some very good advice he gave me ..... eat! I tend to stop eating once it gets dark. It's night ... who eats at night? Plus it can be hard to get at my food in the dark if I haven't prepared very well. And the less I eat, the greater the chances I'll have a wild hallucination. So if I'm riding through the night I have to make an effort to keep eating regularly.