A Non's Perspective:

Chances are, you display a lot of confidence right? People are typically drawn to confidence. What do you pretend to offer them? You likely don't display any faults or weaknesses and seem like a great person to be around. Who wouldn't typically want to be around someone like that? Everyone wants to feel like they're worth it, and if you, someone who seems "perfect" or nearly so, thinks that an individual is worth it (or at least, you likely appear to display that thought to them) then they must actually BE worth it and that's a good feeling.

If you don't want people to be around you so much, try showing them a bit more of your authentic self They'll likely back away quickly. You don't need to be explain anything to them - just try being authentic and they'll get the picture pretty quickly and give you lots of space!

((I'm basing this off my younger brother - he's very much NPD. He's very much idolized by his friends, and I can see why - he treats them really well because they serve a purpose to him. But if those friends have also befriend me, or my parents, and thus know what we're actually like... they'll then start to see through my bro's portrayal of us, and if they happen to see him at "home" and how he actually behaves? They tend to start drifting away from him quickly because they can start to put two and two together. He's only ever lost the friends who've seen the authentic him, which he typically only shows around family.))