I am almost never, ever aware when I'm dreaming - maybe once or twice that I remember? Thing is, I find them so immersive that I never think that I might be. I take on a character, and that character has fake memories, a fake personality, the lot - and any of my awake memories are utterly gone. Some dreams have felt like they've lasted for years. One in particular was about this lifetime I had with an amazing friend who I was bonded to when they were born - when I woke up (after they had died) I nearly cried. Obviously when I remember them I notice the things that should give it away - time jumps, location jumps, but they're always bridged by a whole ton of fake memories that make it seem like I did experience all that time.