Colleague resigned

Yesterday I got a shocking news that my fellow colleague, Malindi, has resigned & her last day was today! Oh it has seemed to be a bit too quick for such change of situation to sink in. Remember Day 1 of work, we went through bits & pieces of Orientation together. And it was barely 6 weeks & she is going, in fact gone now. It is definitely unexpected. Not for someone who has just begun to settle in to be going. Oh well.. Dunno if it is the structure of the organisation that she is getting fed-up. This actually put me into thinking whether i wld have left if i was given a choice....