It is true:
You DON'T need to get high to make a beat.
BUT... When you're in an altered state of consciousness, your brainwaves move differently, thus coming up with something you may not have thought of while sober.
The same goes for staying up until the next day. When your mind is craving REM sleep, you experience an altered circadium or ultradium rhythm (these are points in the day that mirror REM sleep, every 70 to 120 mins, usually associated with staring and being in a "hypnotic" state).
I have found that I am most creative when I have stayed up all night, and the next day I can come up with some SHIT. I used to do that in school, when I was workin two jobs and in the studio all night. I (and others) found that I have a better sense of humor, more witty, and more creative when this happens. (Usually a little crazy too
But if those of you ONLY make a beat high... make sure you're making some (one or two per year even) NOT high. It's a good balance and a way to practice your methods.
I had gotten to a point (12 years ago) when all I would do is smoke weed. I told myself that I had to have something to show for it (e.g. write a rhyme, make a beat, make a freestyle tape, draw a picture, write a poem... something in hard copy). It worked, and a year later, every time I smoked it would be a trigger for my creativity. My boys would pick me up on a Friday night and we'd smoke, then a half hour later I'd say "DROP ME OFF AT THE CRIB!!!", to where I would lock myself in the studio til dawn.
I still get these really strange and sudden rushes of motivation when I smoke today. It's weird how we can all be conditioned by stimulus.
-Hypno.