Anupam Kher has shared a video on Twitter wherein he can be seen signing his autobiography, 'Lessons Life Taught Me, Unknowingly', for ex-United Nations Secretary-General Ban Ki-moon at a gala event. "My most cherished moment was when 8th...#SecretaryGeneral of @UN...asked me to sign my autobiography for him. Him saying #Dhanyawad at the end was real clincher for me," he wrote.