BEWARE!!! My theory of evil RANDOMNESS!!
I just read AYET's blog on Zoro slaying the dragon on PH and I wanted to write a comment but I figured it deserves an own blog instead. - Spell it with me, people: F-U-N-N-Y! This blog is for sole entertainment purpose. I'd put markers in the text that indicate when you're supposed to laugh but I'm too lazy.
During the time skip, Zoro didn't train as much as the others because he spent more time trying to find the way between his bed and the training ground than actually training. On the last day of training he finally managed to find the way without getting lost for the first time. That impressed Mihawk so much, he rewarded him with the God-Mode No Mi, a devil fruit that rises your strength with every One Piece chapter being published, without cursing you with the disadvantages of ordinary DFs.
Little did Zoro know that 10 years prior to the start of the series Mihawk had cut the ocean into two with his Awesomeness-Haki engulfed sword and led his people to Raftel to save them from enslavement by the World Government. Unfortunately, Mihawk's sense of direction at that time was even worse than Zoro's and he got lost on the straight path and ended up on that creepy island where he build his castle on the spot he received the God-Mode No Mi from Satan in exchange for his shirt.
10 years later Mihawk read a fateful newspaper on his flight back from Marine Ford to Kuraigana Island. The paper contained an article about Charlie Sheen being replaced by Ashton Kutcher. Once he got home Mihawk committed harakiri while looking at photos of Kokoro published in the June Issue of the Playboy, causing him to cough out the God-Mode No Mi.
Moments later the dying Mihawk was found by Bon Kurei, who had miraculously escaped Impel Down by turning into Usopp and doing the monkey. Mihawk told Bon his dying wish of passing the DF down to whoever proves to be worthy of it. He also asked Bon to do a Chuck Norris impression but unfortunately the latter couldn't fulfill that wish. (Somewhere in Soviet Russia, Chuck Norris turned into Bon Kurei and caused people to shit enough bricks to build a copy of the Kreml. They sold it to Las Vegas and a few people got very, very rich.)
It was then when Zoro and Perona arrived. Afraid of being accused of the murder, Bon Kurei turned into Mihawk and trained Zoro for 2 years. Nobody ever found out because Zoro was too busy getting lost and Perona was too busy guiding him.
After they had left the island Bon Kurei traveled to Momoiro where "Mihawk" and Ivankov got married, which is why the latter wasn't there to see Sanji off.