Usually because I wish to learn 더 많이 about them if they manage to draw my attention just like with every type of Character. Imagining the possibilities they can 또는 could bring on the 표, 테이블 in the meantime is also a nice pastime. And there are also the times I can respect 또는 even relate to some of their reasons for keeping the Mystery to them like the fact that being an entirely open book in the past didn't do me as much good when dealing with certain people !!!!