It's a phrase that can be used in a few different ways:
* To express admiration and gratitude: This could be said to someone who has done something kind or generous for you.
* To express a feeling of being undeserving: You might say this if someone is treating you exceptionally well, and you feel you don't deserve it.
* To hint at a romantic interest: Sometimes, it can be used to express feelings of affection or admiration for someone.
The specific context will determine the exact meaning.
Let me know if you'd like me to give an example of how to use this phrase in a sentence!