This is a lovely ideal - complete openess, honesty, joining as one.....
But while i would never advocate lying to your partner, the reality is that every day we present ourselves differently to different people. We don't lie, they are all aspects of us, we just show different sides in different situations.
i guess it could be viewed as manipulative, but it's how society functions.
The problem only arises if one is deliberately untruthful or neglects to mention something that they know their partner would want to know.
And as time goes on, your partner will see all the "yous", the one you present to your mother, your friends, your co workers, your kids, and get a truly rounded view of you.
But in my opinion it's only natural to present yourself at your best when embarking on a relationship, and there are appropriate times for certain revelations, not neccessarily the first date.