I'm a non-traditional student (first gen college student / first gen american), so when I wrote my SoP I started by talking about my background, life challenges, etc. My advisor told me not to do this. She said to reverse it and start with my research interest, and bring in my background towards the end to fill in the gaps and connect my research to who I am. In that way, I kind of forwent the idea of having a personal "hook" and just talked about my field of interest, research, etc. until the end of the piece and it worked out for me.