Closing line of
纳兰性德 《浣溪沙·谁念西风独自凉》 (Qing, late 17th c.), written mourning his deceased wife. He stands in the dying sun lost in memory of small shared moments - drunk on wine he never startled her heavy spring sleep, betting over books they would spill the fragrant tea - and ends:
当时只道是寻常 ('at the time, I just took it to be ordinary').
纳兰 is the undisputed king of Qing lovesick ci.