For instance: this is a dog.
This is also a dog.
So is this.
And so is this.
Now consider this furry creature.
So how do we automatically know the difference?
And more to the point: how could an alien, with no special connection to either species, be expected to know the difference? How could an alien tell that the first four animals are all dogs, even though there are such striking differences between breeds; or that, even with all its visual similarities, a fox is not a dog?
This is what I mean by having to try to unlearn things. We are human, so we think like humans, and we tend to assume that aliens would relate to each other and to us as though they were humans too. But being human means carrying around a HUGE volume of knowledge and assumptions -- some global, some culture-specific -- that aliens wouldn't have had a chance to accrete. Instead, presumably, they have their own volume of knowledge and assumptions which might be quite different from ours. And trying to think like an alien -- to create an artificial set of knowledge, culture, behaviors and mores not completely based on human knowledge -- is hard. Our cultural assumptions and all the things we instinctively know keep tripping us up.
What do you think? Have you written any SF stories involving aliens, and if so, what are your tips and tricks to create a truly alien point of view?