Strange obsessive thoughts

I know for a fact this is far different from depression.(considering I am diagnosed with it) The feel of this is entirely different. I like to imagine situations where I die...but never feel the urge to follow through with these thoughts. I am amused by it, almost like I use it to pass time. I swear to God that if i get admitted again I will strike the person who admits me. Those darn people ask the same questions repeatedly expecting different results, and i may be mistaken but isn't that the definition of insane? Anyways I am looking for a logical explaination for these obessive thoughts.