The Challenges of Studying Dreams

Why are dreams so hard to study? One of the biggest difficulties is that we don't study dreams directly. We usually can only know once we wake up the individual and he or she tells us about the dream they were experiencing. So dreams are a private, sujective experience. But these challenges an studying dreams aren't unique to dreams. You find them in many other areas. For instance, in the study of pain. When we study pain, you can't have a machinery that allows you to see the pain. Such an interesting analogyit never occurred to me to think of it like that.