Yeah, I had in mind that you can't get away from some of the basic building blocks of your character. For example, you can't acquire a different native language - though you can learn to speak a foreign language like a native. But we think in words, so the words with which we grow up are always likely to exercise a formidable influence on the way we think.
And, not to be Freudian, there are things that happen to us while we're young that have a similarly weighty impact. I think I've resisted authority since I was five or six, due to (failed) political indoctrination in the schools I was sent to in those days.
MG