User blog comment:Diwosh/Luffy's mom/@comment-95.105.212.107-20130408152128

Meybe she is dead. Meybe when Dragon was younger he married a girl from Goa kingdom and lived there for a while. After Luffy was born a celestial dragon came to the kingdom. Luffys mom was in the wrong place at the wrong time and the celestial dragon killed her. After Dragon had leraned of this (or seen it) he decided that he wants a world in which his son can live free. He rejected Garps idea about him joining the marines and created the resistance. It would certainly explain his motivation behind it. It would be certainly an interesting plot twist if Luffy met that celestial dragon that killed his mom and the celestial dragon would brag about it infront of him.