年少轻狂不知梦放荡不羁不知痛
[nián shăo qīng kuáng bù zhī mèng fàng dàng bù jī bù zhī tòng]
Translates to 'reckless when young, unaware of dreams, unruly and uninhibited, ignorant of pain'. It refers to those youthful days filled with audacity, lack of responsibility and foresight about life and love.