great (esp. BrE), real, true
old (esp. BrE)
hopeless, incurable

be a romantic at heart

be, feel, look, seem, sound
become, get
You're getting very romantic in your old age!

extremely, fairly, very, etc.
highly
highly romantic notions of marriage

incredibly, terribly, wildly, wonderfully

Romantic is used with these nouns:
ballet, adventure, affair, atmosphere, attachment, backdrop, bliss, comedy, couple, dinner, disappointment, drama, dream, encounter, era, evening, fantasy, feeling, fiction, gesture, hero, heroine, idea, ideal, illusion, imagination, interlude, lead, liaison, love, meeting, mood, movement, movie, myth, notion, novel, novelist, overture, painter, partner, passion, poet, poetry, relationship, rendezvous, restaurant, rival, scene, setting, soul, stroll, tale, temperament, touch, view, vision, walk, yearning