My first lucid dream involved a large buffet of unpleasant foods. When I was seven-ish, I had a series of lucid dreams which were interconnected. This was when I first learned the technique. I had a staff which could emit lasers, and eventually, I learned to emit lasers from my fingertips and no longer needed the staff. This was my reality check; if I could emit lasers, I was dreaming.
This wasn't a lucid dream, but it was amusing nonetheless. I was standing in the library, blowing my nose very noisily into a tissue. When I finished, I turned around and was shocked to see a man staring back at me. I apologized for being disgusting. A moment later, I handed him the tissue and said, "Do you want it?" He said, "Yes!" and took it.