pot, in its greatest form trips you out this way(i finally found the perfect explination): you're paying attention to something and then u look at something esle and you're like "was i looking at this thing?...no" and you go back to what you were doing lol, thats the stuff....
I don't know about forgetting what you were doing, but I've been ripped to the point of having the most amazing ideas (how amazing i dont remember roflmao), and forgotten what i was thinkin about in a second, then tried to follow my train of thought back to it for like 20 minutes. I've successfully done this twice, unfortunately I forgot what the ideas were lol.
this sounds like me. or like sometimes ill be talking and ill see something in the corner of my eye and look over at it. and in those like 5 seconds, ill forget what i was saying. then it usually comes back to me in the next 10 min.
It's crazy how stupid ass shit seems so real when your fucked up. Liek oen time I thoguth the whoel world was in my brain.. or someshit.. I really don't remember.