The first computer I used had Windows 3.1, so I'm not sure if I "grew up with" XP.... but no, it looks super dated to me. The icons are OK, the rest of Luna is fairly ugly.
There might be something to your theory, though - I think the Windows 2000 design still looks pretty good, although the colour palette is broadly too dark and saturated by modern standards. Perhaps we just get attached to the systems we remember liking.
This - nostalgia is a huge factor. However, I used OSX very little and still think their pre-Yosemite traditional skeuomorphic icons were the best ever. Other elements of their UI weren't good, but the icons were simply beautiful to work with.
There might be something to your theory, though - I think the Windows 2000 design still looks pretty good, although the colour palette is broadly too dark and saturated by modern standards. Perhaps we just get attached to the systems we remember liking.