"almost certainly don’t" is strong language - but they're not saying you don't. I'll interpret as meaning that most of our memories were "implanted" but by no means all.
I have very strong visual memories of events from when I was still in a crib to the present. Lots of those memories are from when I was alone so there was nobody who could have implanted them.
Also, neuroscience says (unless theories have changed) that all memories are "implanted" in that memory works like DRAM. Every time we remember something, it's getting retrieved and then written back to long term storage. It's a destruction-recreation process.
I have very strong visual memories of events from when I was still in a crib to the present. Lots of those memories are from when I was alone so there was nobody who could have implanted them.
Also, neuroscience says (unless theories have changed) that all memories are "implanted" in that memory works like DRAM. Every time we remember something, it's getting retrieved and then written back to long term storage. It's a destruction-recreation process.