Not my memory, but that of a four year old girl I worked with in public childcare. Her older brother was off with his group on a swimming trip. She was sitting beside me drawing and chatting.
"I used to be a good swimmer." she said casually.
"Oh?" I said
"Yes. I used to swim out to the island"
"What island was that, now?"
"Oh, the island. I used to swim there and swim back."
"I see.", I said, noting the hair raising a bit on my arms. "Why did you stop swimming to the island?"
"Oh well... one day I swam out to the island and I just didn't come back. Is it snack time soon? I'm hungry."

Note: I am an avowed agnostic, and though I enjoy the idea of reincarnation, I don't for one second believe in it. But that is pretty much the spookiest conversation I ever had with a young child.