Very true. For me I am always confronted with this with aquatic life in particular. I've spent the majority of my academic career studying our closest relatives. I nit pick and try and find exactly what separates us from these organisms (and there isn't much). But with aquatic life - everything is different. They are really aliens. They may be as close to studying alien life as we'll ever get.Not enough people appreciate just how strange Earth actually is.
If you ever get to Chicago, go to the Field Museum of Natural History. They have a whole display on Pre-Cambrian life with really cool models and exhibits; there's another I remember they have about the Carboniferous period that is amazing, too, as they built a 6 foot centipede for display. It's awesome to look at artists' reconstructions of what the world may have looked like throughout history. Alien, indeed.