My daring

Unfortunatelly, I believe all people once time lie,  maybe is a characteristic from our human, see some reasons:

Greed - for power, for advantage, for money, for admiration

Fear - we are sometimes driven to lie by fear - usually of what will happen if we tell the truth

Acceptance - no man is an island. We find ourselves doing whatever it takes to be accepted, to be liked and appreciated

Habit - compulsive liars lie compulsively because they are used to it

Find more: http://www.bbc.co.uk/dna/h2g2/A996942