Ozymandia's

I found this poem a little difficult to understand when I read it the first time, but when I read it over and over I picked up things that I did not get the first time. I took the lines one by one to try to understand it better. What I got out of the poem was that when Ozymandia was out in the dessert he meet a man that had being dying. The old mans body was tour apart and he was left their to rot and Ozymandias was telling him that he was the king of kings. I think that he was telling him that because he wanted the old man dying to bow down to him or something. Thats what I got out of it when I read the poem.