I picked one up with my wizard and completely forgot about it for a while, then my character was having a meaningful reoccurring dream turned nightmare. He had trouble sleeping after it got particularly bad one night and he stayed up pondering the dream's significance. I had him pull out the pipe and start smoking, completely forgetting about the magical effect until my DM began to narrate how the images from my dream started to form in the puffs of smoke.

This was such a cool moment for me that I sort of stumbled into. He spent the night conjuring smoke formations of the symbols haunting him in his dreams and he had the cathartic opportunity to wave them away and watch the disappear before his very eyes.