I believe everyone of us has lied directly or by omission at one time or another dating back from early childhood. It's human nature to want to avoid pain. Whether one seeks to avoid feeling the raft of pain from someone else or causing pain to another; person people lie.
Oftentimes we lie about how we (feel) or what we're really thinking.
They sometimes lie to avoid disappointing others.
Sometimes people tell "white lies" not to hurt people's feelings.
"You can be anything you want." "No, you don't look fat in that dress."
In other instances it is to encourage wonderment about life "Santa Claus, the Easter Bunny and Tooth Fairy" are all lies told to children by parents.
Sometimes people lie to keep secrets: There's a surprise birthday party or upcoming marriage proposal that is planned...etc
Your boss, sibling, friend or whomever confides in you and you promise not to reveal their secret if anyone asks.
Some people lie to (impress or win) over new admires.
People lie on their resumes about past job experience, education, or previous salary. They claim charitable deductions on their tax forms that were more than they actually donated. The list goes on.
My point is anyone who says they don't or have never lied is lying!:)
We simply have our own definition of what is a justifiable or white lie.