"Don't forget your original thoughts" means don't forget to go against your original dreams and beliefs. Don't forget your innovative spirit, so as to achieve your ultimate goal.
There are four words in Hua Yan Jing, which have the same meaning as "Don't forget your original heart". "No" means "No". Now many young people run counter to their original dreams when they grow up. At this time, they need to persist, adhere to their original beliefs, and unswervingly go on.