I don't think you can generalize from your experience. I drink tons of coffee and have wild dreams every night. They're even wilder on the rare occasions I smoke pot.
I'm not discounting the potential effect of substances on REM, and as a drinker I'm aware of the deficit during the first 4 hours of drunk sleep. But really, I don't think people are talking about dreaming here so much as the perception or recollection of dreaming. I've made a point of keeping a notepad next to my bed for about 10 years. If someone had asked me before that how often I dream, I would've said maybe once a week. I don't think keeping a journal actually made me dream any more often. It's just that once I really made it a habit to access the halfway state by jotting a note every time I woke up, I became aware that I have 3-4 crazy dreams every night. The only exception is drunken blackouts, but I'd lay odds that's because I just don't wake up often enough to write them down.
