A common English mistake that I hear from native Korean speakers is saying "Nice to meet you" after seeing someone they already know. This is because in their head, they're translating the expression 반가웠어요 or 반가워요 incorrectly. A similar thing can happen if a Korean learner is trying to translate Korean to English in their head.
If a Korean uses the verb 반갑다, it doesn't always mean that you're "meeting" someone for the first time. 반갑다 can also be used when you're simply seeing someone again (think "Nice to see you"), but that's not all. 반갑다 actually has an even simpler meaning at its core, and that's what I'll explain in this video.