As someone who used meth almost daily for 12 years, along with many forms of hallucinogenic drugs and ecstasy. Your brain/body gets flooded with endorphins/serotonin that gives you that happy) euphoric sensation. Eventually, you drain that, and it takes more and more to have the same effect as when you first tried it. Causing a bad trip you say, eh, more of you damaging your body and brain. Leading to depression, which may trigger mood swings and other things which may lead you to believe that. Only time you would see shit, if not hallucinating on acid or etc, is when you been up for few days and more. You will start seeing "shadow people", and have paranoia. I used to stay up for 7 days up to 16 or so at a time on meth and would see shit like that. Longest I stayed up for was 22 days. After day 14/15 your brain kinda says f[b]u[/b]ck it. You still have basics functional skills but thats about it.