不忘

keep in mind; never forget; bear in mind; unforgotten

初心

one's original aspiration; original intention; initial aspiration; original heart

始终

from beginning to end; all along; all the time; for evermore; ever more; from start to finish; the alpha and omega; all the while; to the last; of all time; throughout; ever; always; evermore; invariably; long; forever; constantly; the whole time