Quote Originally Posted by Iriba View Post
How can someone know that is dreaming and not remember it?!
Memory is a funny thing that works in mysterious ways. There was one time when I woke up thinking "Yes, I did it! I had a lucid dream!" but then no matter how much I tried, I could not remember my dream. Although it also occurred to me that maybe this was the entire content of this particular dream. The human mind is built to forget dream stuff, and while we are much more likely to remember lucid dreams because we are more aware during them, but the degree of awareness varies and while we may remember some of it but we may forget details, and thus may need to work on improving detail recall even from lucid dreams.

Incidentally, the original question of this tread was about the reverse scenario: trouble remembering goals from waking life inside dreams. And that is quite likely because when lucid we may not have access to all waking memories, again I think it comes down to increasing awareness. By default our dreaming minds are more foggy than waking minds, and thus stuff we would easily know while awake may not be accessible when barely aware - that's also true when awake but very tired. in general memory enhancing techniques in waking life can also translate into better memory in dreams.