of all people/things/places idiom       
 (表示认为不可能或惊讶)在所有的人/东西/地方中(偏偏)
used to express the idea that a particular person/thing/place is unlikely or surprising
  Donna, of all people, is the last one I'd expect to see at the gym. 我万万没有想到会在健身房里见到当娜。 
 And why did you choose Iceland for a holiday, of all places? 那么多的地方,你为什么偏偏要去冰岛度假?