Mistakes and the Truth

"The decisions we take really consciously, after having considered a lot of options and alternatives, are mostly those, that go against our nature" - I heard two ladys talking yesterday on my way home.
That's an interesting thought, especially if consider it's consequences and implications. Whenever we make mistakes (not wrong decisions, just simple mistakes), we are in most cases not really consciuos; they just happen – shit happens.
So does this mean our mistakes are, who we really are?