Dogs and cats are companion animals, incidentally and intentionally selected to have behavioural phenotypes that make them amenable to that role. A wild octopus isn't quite the same. I've had quite a few marine animals in captivity and while octopus are intelligent, I think a bit too much is being made of some of these anecdotes relative to that. For example, small freshwater crayfish which I don't think anyone would argue have the intelligence of a pig or octopus still display the interindividual difference in personalities, preferences etc in a tank.