I don't think people should flush dead fish down a toilet. Is there just something wrong with my head?

Same here.  I ended up burying my beloved fish in the backyard.  He had a pretty container to go in.  I cringe when people flush their fish down the toilet.  It's the same as your dog or cat... give them a proper burial.  We must have respect for the dead as we do the living.      

I agree with you.

It’s also very bad if they died from water born parasites or bacteria that you would now being added to the local water system if you flushed. 

Me personally, I like to put them outside where nature can eat them. Usually within a few hours Birds, cats or insects will get to them. But it all Depends on the size of fish, how it died and if the fish is definitely dead. If it’s dying, I think that’s cruel to flush it before it dies. The fish will suffer more as it goes through the sewer/septic system. 

My fish are generally too big to simply flush. Living on a dead end, I bury them in a particular place and in the spring, the local gardener-a friend-know where to go for the best dirt for the flower bed. 

Its not good for the toilet either.  

I get where you are coming from but they are dead so it doesn't matter what happens to them. I am the kind of person that goes above and beyond for my pets but once they are dead they go in the trash. Fish get large tanks, live plants, heaters, filters, regular water changes, quality food, proper stocking, medications when needed etc but when they dead they go right in the trash. If burying your pets is what you need to help you cope and to help you move on then absolutely do that but other people like me move on when the animal passes and don't feel the need to do anything special with the body. There is absolutely nothing wrong with you. Everyone processes loss differently and many people cannot even fathom throwing a pet in the trash and that's completely normal and valid but not the only way to do things. 

everyone does things different