For instance i have hallucinated twice, both after eating firecrackers. The first time i was driving from the grocery store at night and i thought there were many cats jumping in unison on the crosswalk. the second time i was reading a book in the living room of my friends cabin and i thought his siblings were playing monopoly in the room and wanted me to play, when i finally looked up there was nobody in the room and everyone was outside.
I don't think these really count, but sometimes I see things on the side of the road and mistake them for people. only happens when its dark.
Never... the closest would be confusing my memories with daydreaming, like I'll be imagining certain things and then wonder if they really didn't happen.
At high doses after not smoking for some time, I will occasionally see a similar kaleidoscope pattern to the one that you would get when you rub your eyes really hard. I've always chalked it up to oxygen deprivation, though, as it last about as long as your usual head rush.