[There was a pause as he caught the distinction, but didn't comment on it. He knew where Leia stood, and he knew where he did, there was no need to discuss it.]
It's difficult to say. But if I were to guess, I would say from a young age.
Anakin was brought into the Jedi Order when he was 9 years old. Palpatine had access from that time on. He took on the role of a friend and a mentor, having plenty of time to slowly and subtly affect his mind.
Such methods are... the most effective, and the hardest to break. A young mind is easily molded. He likely did not even realize it, hence why he can't remember.
Voice;
It's difficult to say. But if I were to guess, I would say from a young age.
Anakin was brought into the Jedi Order when he was 9 years old. Palpatine had access from that time on. He took on the role of a friend and a mentor, having plenty of time to slowly and subtly affect his mind.
Such methods are... the most effective, and the hardest to break. A young mind is easily molded. He likely did not even realize it, hence why he can't remember.