Several people in my life (good friends, family members) who are like that...
- pretend not to drink alcohol (a bottle would be misunderstood)
- always on a diet (so no cakes/chocolates)
- shopping vouchers not good enough (lazy, not sincere)
- don't read books/watch films/listen to music
- very peculiar taste in jewelry/cosmetics (only they know what up to their taste)
- home deco (again, never good enough)
- don't have hobbies
if these people weren't close, i wouldn't care, but one of them is my own mother...