I've thought about that. But, that's kind of like thinking the universe began when you woke up this morning, upon which all of your memories were implanted into your consciousness, or the possibility that everyone in the world is an actor or a figment of your imagination. It's possible, but we typically try to avoid those kinds of thoughts in fear of becoming insane.
So, I choose not to believe that somehow my memories are fabricated. No one has pointed out any inconsistencies in my memory, so far. So, I think I'm okay, for now.
I either want to be an alien and force sex upon a female abductee, get abducted by a female alien and get tied up and repeatedly fucked, or be an alien and have slow and passionate sex with another alien in some weird kind of warm goo.