It's the feeling of being possessed by desire. When you ask people about being limerent it’s not atypical to hear “It almost ruined my life,” sometimes followed by “I miss the intensity of it.”
Katherine Anne Porter in an interview once said "I made the mistake of thinking I was quite like anyone else, of trying to live like other people. It took me a while to realize that simply wasn’t true. I had my own needs, and I had to live like me.”
You can tell when someone is quietly confident. When they have a concise sense of their own identity — they don’t need to overcompensate or speak loudly about their successes or wealth or intensity