I'm going to assume that you have read the riddle now. Assuming is a big part of this riddle. The only thing you can deduct from all the clues is that you CAN'T determine what pet the German has. He must have a pet and therefore, he's the only one who could possibly own the fish. Yeah, yeah...he's in the green house, smokes whatever, drinks whatever.
He has to be the one that owns the fish. That conclusion seems to be unanimous among those solving this puzzle. Almost everyone comes up with the same answer. Why is it said that only 2% can solve this puzzle? It's just not that hard of a puzzle. Nobody gets it wrong.
Not so fast.
I didn't even bother to go through all that, because for me, the answer was in the clues immediately. Just look at these clues:
The Swede has a dog for a pet.
The person who smokes Pall Mall rears birds.
The person who smokes blend lives next to the person who keeps cats.
The person who keeps horses lives next to the person who smokes Dunhill.
See the clues? Pay careful attention to the wording. Words have meaning here.
Who among you has a Dog for a pet? Aren't they the most loyal animals you know of? They'll let you know when someone's around when you can't even hear them. If there is a threat, they know first. When in trouble, most of them will defend you with their life. Regardless of size. The small ones keep some of our feet warm at night.
Birds. What other animal can mimic your voice? Some of them talk to you. Others hunt. They sit on your shoulder. Some are dangerous. Others are just plain goofy. Some of them live much longer than you ever will. The loyal bird is the one that stays with you. The one on your shoulder. Birds require the most trust. They can leave you whenever they want.
Then, there are the cats. Who has a cat living with you? Now aren't they a boatload of fun? They disappear for days on end and come back wondering why you were worried. Ever have one bring you a "present"? They drop a mouse at your feet and wonder why aren't thrilled. This is an animal that will get along just fine without you. It doesn't need you. Cats don't come when you call them, they take a message and get back to you later. I like cats.
The horse. Where would we be without them? They used to plow our fields, pulled our wagons and carried us into battle. Have any of you tried to break one of these animals? Or rope one? It isn't easy. But when you make friends with a horse, you have one very loyal friend. In the past, a horse could save your life or get you killed.
Look at the key words again:
HAS a dog for a PET, REARS birds, KEEPS cats, KEEPS horses.
Nobody else in this riddle OWNS any animal.
Starting to re-think things a little? I sure did. The only thing you can conclusively prove from the clues is that you don't know what sort of pet the German has. Only that it is different from the others. You have to assume he owns the fish. The German could have a kangaroo for a pet. The question is still: Who OWNS the fish?
Forget the riddle. Imagine youself and a child standing on the beach. Any beach. Looking out over the water, the child asks, "Who OWNS the fish?" What would your answer be now?
A dog can leave. A bird can fly away. A cat doesn't really need you at all. And a horse? That's up to him. He has a lot more say than you do.
Even though your fish can't run away, I seriously doubt if you dropped him in a river he would ever swim back and want to go home.
I sort of like it out here in left field. I don't care if I'm in the 2% or the 98%. I'm sticking with my answer.
What's my answer?
No matter how much you love your pet, you're never going to OWN it.
GOD does. Consider yourself lucky if he loaned you one.
And that puzzle nearly drove me nuts. I am NOT one of the 2%. If the green house was to the left of the white one, which side of the street were the houses on? So on & so on. The more I figured the more confused I felt!
I gave up, which is something I don't do well. It was a good puzzle.
If you ignore the obvious play on words, it was a legitimate riddle and was fun. I don't think you opened a can of worms here, you just stated a different approach and I find nothing wrong with that at all. In fact I believe you to be as correct as those who took the other approach.