Romanticism was the practice of idealizing someone or something while ignoring their negative qualities.
According to Elim Garak, Damar had a romanticism for the past. When Kira Nerys confronted him in 2375 with the parallels between his people's actions against the Bajorans and the Dominion's actions against his wife and son, he was startled and took a step toward her. After Kira criticized herself for speaking so boldly to him, Garak assured her that he needed the jibe. (DS9: "Tacking Into the Wind")
That same year, Tom Paris and Tuvok returned to the USS Voyager following being trapped on a class D planet, during which Tuvok developed a relationship with a woman named Noss, which he refused to allow to blossom into a romance due to his Vulcan teachings regarding the suppression of emotion. The two had been trapped on the planet for a period of approximately two months, but due to a time differential, only two days had passed on Voyager. Paris express to Tuvok the oddity of having greatly missed his wife, only to find that she did not feel the same way because of him only being gone two days in her point of view. Tuvok responded that he was sure she would have experienced a deep feeling of loss if not for the time differential. To this, Paris replied that "I always thought that beneath that cold, Vulcan exterior lay a even colder Vulcan interior. Now, I'm convinced you're a hopeless romantic" and Tuvok stated that there was no need to insult him. (VOY: "Gravity")