My Scientology Blog: Bad Memories:
"[...] Scientology Auditing does not erase memories as the article implies that the drugs do.
Auditing erases the trauma associated with the memories. The memories themselves are still there, it's the pain and suffering associated with them that is gone.
If you had an accident and the memory was completely removed then you could easily make the same mistakes again and repeat the accident. If you have the trauma removed then you can remember exactly what happened and thereby learn from your mistakes.
I think that's a much better solution."