I'm atheist, 'O Paalanhaare' is most challenging song I wrote: Javed

Veteran lyricist Javed Akhtar termed 'O Paalanhaare' the most challenging song that he has written. "Even as an atheist, I had to find innocence and surrender in my heart. You can’t write such songs with tact and craft; it can only be done with purity and simplicity," he added. The song was part of the 2001 film 'Lagaan'.