So everything up until now was what happened in the first life. He went back to the past and let it all play out and basically waited all this time to meet Martin again. He was about to give up when the Martin of this second life found him by chance. Martin doesn't have memories of the first life. So that's why Sinclair was crying a bit when he introduced himself. I hope this helps. I've also previously left this tidbit of info as a reply to a previous comment.