London, June 23 : Actress Angelina Jolie says being a mother has been one of the greatest surprises of her life and her maternal feeling deepened after she started adopting children and living with Brad Pitt.Jolie raises adopted children Maddox, nine,Pax, six, Zahara, five, and biological kids, Shiloh, five, and two-year-old twins Knox and Vivienne with partner Pitt."It's been one of the great