it is totally random for me , but if i don't smoke I will stay up so much later and not get as much sleep. The cool thing about dreams is you can control whatever is happening, you just have to think hard enough.

for example, i had one dream where i was pulled over by the cops and they took my stash. If you can tell yourself that you are dreaming and none of this is real you can do whatever you wish to those cops.... its really fun and challenges your mind power i guess